To investigate the effects of ischemia-reperfusion on the levels of nitric oxide and nitric oxide synthasc isoforms (nNOS and iNOS), rat organotypic hippocampus slice were cultured in vitro and subjected to ischemia...To investigate the effects of ischemia-reperfusion on the levels of nitric oxide and nitric oxide synthasc isoforms (nNOS and iNOS), rat organotypic hippocampus slice were cultured in vitro and subjected to ischemia by oxygen glucose deprivation (OGD) for 30 min and then placed in the normal culture condition. The ischemia-reperfusion produced a time-dependent increase in nitrite levels in the culture medium. Reverse transcriptional-polymerase chain reaction showed augmented levels of mRNA for both nNOS and iNOS when compared with control at 12 h and remained increase at 36 h after OGD (P〈0.05). The protein levels of both nitric oxide synthase isoforms increased significantly as determined by Western Blot. OGD also caused neurotoxicity in this model as revealed by the elevated lactate dehydrogenase (LDH) efflux into the incubation solution. The resuits suggest that organotypic hippocampus slice is a useful model in studying ischemia-reperfusion brain injury. NO and NOS may play a critical role in the ischemia-reperfusion brain damage in vitro.展开更多
With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic...With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic rate.However,few therapeutic options exist that can markedly improve the cognitive impairment and prognosis of vascular dementia patients.Similarly in Alzheimer’s disease and other neurological disorders,synaptic dysfunction is recognized as the main reason for cognitive decline.Nitric oxide is one of the ubiquitous gaseous cellular messengers involved in multiple physiological and pathological processes of the central nervous system.Recently,nitric oxide has been implicated in regulating synaptic plasticity and plays an important role in the pathogenesis of vascular dementia.This review introduces in detail the emerging role of nitric oxide in physiological and pathological states of vascular dementia and summarizes the diverse effects of nitric oxide on different aspects of synaptic dysfunction,neuroinflammation,oxidative stress,and blood-brain barrier dysfunction that underlie the progress of vascular dementia.Additionally,we propose that targeting the nitric oxide-sGC-cGMP pathway using certain specific approaches may provide a novel therapeutic strategy for vascular dementia.展开更多
Dysfunction of neuronal nitric oxide synthase contributes to neurotoxicity,which triggers cell death in various neuropathological diseases,including epilepsy.Studies have shown that inhibition of neuronal nitric oxide...Dysfunction of neuronal nitric oxide synthase contributes to neurotoxicity,which triggers cell death in various neuropathological diseases,including epilepsy.Studies have shown that inhibition of neuronal nitric oxide synthase activity increases the epilepsy threshold,that is,has an anticonvulsant effect.However,the exact role and potential mechanism of neuronal nitric oxide synthase in seizures are still unclear.In this study,we performed RNA sequencing,functional enrichment analysis,and weighted gene coexpression network analysis of the hippocampus of tremor rats,a rat model of genetic epilepsy.We found damaged hippocampal mitochondria and abnormal succinate dehydrogenase level and Na+-K+-ATPase activity.In addition,we used a pilocarpine-induced N2a cell model to mimic epileptic injury.After application of neuronal nitric oxide synthase inhibitor 7-nitroindazole,changes in malondialdehyde,lactate dehydrogenase and superoxide dismutase,which are associated with oxidative stress,were reversed,and the increase in reactive oxygen species level was reversed by 7-nitroindazole or reactive oxygen species inhibitor N-acetylcysteine.Application of 7-nitroindazole or N-acetylcysteine downregulated the expression of caspase-3 and cytochrome c and reversed the apoptosis of epileptic cells.Furthermore,7-nitroindazole or N-acetylcysteine downregulated the abnormally high expression of NLRP3,gasdermin-D,interleukin-1βand interleukin-18.This indicated that 7-nitroindazole and N-acetylcysteine each reversed epileptic cell death.Taken together,our findings suggest that the neuronal nitric oxide synthase/reactive oxygen species pathway is involved in pyroptosis of epileptic cells,and inhibiting neuronal nitric oxide synthase activity or its induced oxidative stress may play a neuroprotective role in epilepsy.展开更多
Treatment with metformin can lead to the recovery of pleiotropic biological activities after spinal cord injury.However,its effect on spinal cord injury in aged mice remains unclear.Considering the essential role of a...Treatment with metformin can lead to the recovery of pleiotropic biological activities after spinal cord injury.However,its effect on spinal cord injury in aged mice remains unclear.Considering the essential role of angiogenesis during the regeneration process,we hypothesized that metformin activates the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway in endothelial cells,thereby promoting microvascular regeneration in aged mice after spinal cord injury.In this study,we established young and aged mouse models of contusive spinal cord injury using a modified Allen method.We found that aging hindered the recovery of neurological function and the formation of blood vessels in the spinal cord.Treatment with metformin promoted spinal cord microvascular endothelial cell migration and blood vessel formation in vitro.Furthermore,intraperitoneal injection of metformin in an in vivo model promoted endothelial cell proliferation and increased the density of new blood vessels in the spinal cord,thereby improving neurological function.The role of metformin was reversed by compound C,an adenosine monophosphate-activated protein kinase inhibitor,both in vivo and in vitro,suggesting that the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway likely regulates metformin-mediated angiogenesis after spinal cord injury.These findings suggest that metformin promotes vascular regeneration in the injured spinal cord by activating the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway,thereby improving the neurological function of aged mice after spinal cord injury.展开更多
Background Exposure of adult mice to more than 95% O_2 produces a lethal injury by 72 hours. Nitric oxide synthase (NOS) is thought to contribute to the pathophysiology of murine hyperoxia-induced acute lung injury ...Background Exposure of adult mice to more than 95% O_2 produces a lethal injury by 72 hours. Nitric oxide synthase (NOS) is thought to contribute to the pathophysiology of murine hyperoxia-induced acute lung injury (ALI). Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages. OPN inhibits inducible nitric oxide synthase (iNOS), which generates large amounts of nitric oxide production. However, the relationship between nitric oxide and endogenous OPN in lung tissue during hyperoxia-induced ALI has not yet been elucidated, thus we examined the role that OPN plays in the hyperoxia-induced lung injury and its relationships with NOS.Methods One hundred and forty-four osteopontin knock-out (KO) mice and their matched wild type background control (WT) were exposed in sealed cages 〉95% oxygen or room air for 24-72 hours, and the severity of lung injury was assessed; expression of OPN, endothelial nitric oxide synthase (eNOS) and iNOS mRNA in lung tissues at 24,48 and 72 hours of hyperoxia were studied by reverse transcription-polymerase chain reaction (RT-PCR); immunohistochemistry (IHC) was performed for the detection of iNOS, eNOS, and OPN protein in lung tissues.Results OPN KO mice developed more severe acute lung injury at 72 hours of hyperoxia. The wet/dry weight ratio increased to 6.85±0.66 in the KO mice at 72 hours of hyperoxia as compared to 5.31±0.92 in the WT group (P〈0.05). iNOS mRNA (48 hours: 1.04±0.08 vs. 0.63±0.09, P〈0.01; 72 hours: 0.89±0.08 vs. 0.72±0.09, P〈0.05) and eNOS mRNA (48 hours: 0.62±0.08 vs. 0.43±0.09, P〈0.05; 72 hours: 0.67±0.08 vs. 0.45±0.09, P〈0.05) expression was more significantly increased in OPN KO mice than their matched WT mice when exposed to hyperoxia. IHC study showed higher expression of iNOS (20.54±3.18 vs. 12.52±2.46, P 〈0.05) and eNOS (19.83±5.64 vs. 9.45±3.82, P 〈0.05) in lung tissues of OPN KO mice at 72 hours of hyperoxia. Conclusion OPN can protect against hyperoxia-induced lung injury by inhibiting NOS.展开更多
Neuronal nitric oxide synthase(nNOS)was the producer of nitric oxide(NO)which played important gas messenger molecules in biological process.It also can take effect as immune regulation molecule in organism.Black rock...Neuronal nitric oxide synthase(nNOS)was the producer of nitric oxide(NO)which played important gas messenger molecules in biological process.It also can take effect as immune regulation molecule in organism.Black rockfish(Sebastes schlegelii)is an important economic fish which were widely farmed in East Asia countries.Meanwhile,the pathogenic bacteria such as the Edwardsiella tarda and Vibrio anguillarum in seawater always brought serious obstacles to their healthy growth.In order to explore the expression pattern of n NOS gene under the pathogen stimulation and predict its immune function,the n NOS gene in black rockfish named Ssn NOS was identified.It was 3780 bp in length,located on chromosome 6,and contained 27 coding domain sequence(CDs).According to the phylogenetic analysis,the Ssn NOS showed closest relative to the counterpart gene of swamp eel(Monopterus albus).Meanwhile,analysis of Ssn NOS expression in various healthy tissues showed that Ssn NOS expression level was highest in healthy brain tissues,followed by intestinal tissues.In addition,Ssn NOS showed significant expression changes in response to stimulation by two pathogens.Particular in gill,the expression of Ssn NOS after pathogenic stimulation increased significantly.The Elisa analysis showed the Ssn NOS content in gills was much higher than that in other tissues at all time points.Moreover,the expression patterns of Ssn NOS in brain,intestine and kidney after stimulation by pathogens showed a distinct expression pattern which first down-regulated and then up-regulated.Therefore,the Ssn NOS may be an important signaling molecule for fish to respond rapidly in immune stimulation.展开更多
Objective: To investigate the differen t expression of three isozymes of nitric oxide synthase (NOS) in diabetic rat colo ns and the contribution to the colonic dysfunction. Methods: Sprague-Dawley (SD) rats were us...Objective: To investigate the differen t expression of three isozymes of nitric oxide synthase (NOS) in diabetic rat colo ns and the contribution to the colonic dysfunction. Methods: Sprague-Dawley (SD) rats were used in this experiment and diabetes were induc ed by streptozotocin (65 mg/kg, i.v.). Three isozymes of NOS (nNOS, iNOS and eNO S) expression in proximal and distal colon were measured in two weeks after diab etes induction using the methods of immunocytochemistry and semi-quantitative r everse transcription-polymerase chain reaction (RT-PCR). Results: Positive immunoreactivity for nNOS was found in intermuscular and submucous plexus neuronal cells, neither eNOS nor iNOS had been found in any layers of col on in the two groups. The expression of nNOS mRNA was significantly increased in diabetic colon than that in control rats as determined by RT-PCR. The eNOS mRN A level of diabetic colon was lower compared to thecontrol rats, while no expres sion of iNOS mRNA was found in the normal or diabetic rats. Conclusion: This report has demonstrated that nNOS increased and eNOS decreased in rat colon in the early stages of diabetes. NO production by the nNOS might play a key role in colonic dysfunction, as supported by raised nNOS mRNA and enzyme e xpression in the diabetic colon. Reduced eNOS activity might also contribute to colonic dysfunction in experimental diabetes.展开更多
Aim: To investigate the effect of icariin on erectile function and the expression of nitric oxide synthase (NOS) isoforms in castrated rats. Methods: Thirty-two adult male Wistar rats were randomly divided into on...Aim: To investigate the effect of icariin on erectile function and the expression of nitric oxide synthase (NOS) isoforms in castrated rats. Methods: Thirty-two adult male Wistar rats were randomly divided into one shamoperated group (A) and three castrated groups (B, C and D). One week after surgery, rats were treated with normal saline (groups A and B) or oral icariin (1 mg/[kg·day] for group C and 5 mg/[kg·day] for group D) for 4 weeks. One week after treatment, the erectile function of the rats was assessed by measuring intracavernosal pressure (ICP) during electrostimulation of the cavernosal nerve. The serum testosterone (ST) levels, the percent of smooth muscle (PSM) in trabecular tissue, and the expression of mRNA and proteins of neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS) and phosphodiesterase V (PDES) in corpus cavernosum (CC) were also evaluated. Results: ICP, PSM, ST and the expression of nNOS, iNOS, eNOS and PDE5 were significantly decreased in group B compared with those in group A (P 〈 0.01). However, ICE PSM and the expression of nNOS and iNOS were increased in groups C and D compared with those in group B (P 〈 0.05). Changes in ST and the expression of eNOS and PDE5 were not significant (P 〉 0.05) in groups C and D compared with those in group B. Conclusion: Oral treatment with icariin (〉 98.6 % purity) for 4 weeks potentially improves erectile function. This effect is correlated with an increase in PSM and the expression of certain NOS in the CC of castrated rats. These results suggest that icariin may have a therapeutic effect on erectile dysfunction.展开更多
BACKGROUND: Accumulated evidence indicates an important role for hippocampal dendrite atrophy in development of depression, while brain-derived neurotrophic factor (BDNF) participates in hippocampal dendrite growth...BACKGROUND: Accumulated evidence indicates an important role for hippocampal dendrite atrophy in development of depression, while brain-derived neurotrophic factor (BDNF) participates in hippocampal dendrite growth. OBJECTIVE: To discuss the role of BDNF and neuronal nitric oxide synthase (nNOS) in chronic and unpredictable stress-induced depression and the pathogenesis of depression. DESIGN, TIME AND SETTING: Randomized, controlled animal experiment. The experiment was carded out from October 2006 to May 2007 at the Department of Animal Physiology, College of Life Science, Shaanxi Normal University. MATERIALS: Thirty-seven male Sprague-Dawley rats weighing 250-300 g at the beginning of the experiment were obtained from Shaanxi Provincial Institute of Traditional Chinese Medicine (Xi'an, China). BDNF antibody and nNOS antibody were provided by Santa Cruz (USA). K252a (BDNF inhibitor) and 7-NI (nNOS inhibitor) were provided by Sigma (USA). METHODS: Animals were randomly divided into five groups: Control group, chronic unpredicted mild stress (CUMS) group, K252a group, K252a+7-NI group and 7-NI+CUMS group. While the Control, K252a and K252a+7-NI groups of rats not subjected to stress had free access to food and water, other groups of rats were subjected to nine stressors randomly applied for 21 days, with each stressor applied 2-3 times. On days 1, 7, 14 and 21 during CUMS, rats received microinjection of 1 μL of physiological saline in the Control and CUMS groups, 1 ~ L of K252a in the K252a group, 1 μL of K252a and 7-NI in the K252a+7-NI group, and 1 μL of 7-NI in the 7-NI+CUMS group. We observed a variety of alterations in sucrose preference, body weight change, open field test and forced swimming test, and observed the expression of BDNF and nNOS in rat hippocampus by immunohistochemistry; MAIN OUTCOME MEASURES: ① A variety.of behavioral alterations of rats; ② The expression of BDNF and nNOS in rat hippocampus. RESULTS: Compared with the Control group, the behavior of the CUMS rats was significantly depressed, the expression of BDNF decreased (P 〈 0.01) but the expression of nNOS increased (P 〈 0.01). The behavior of rats given intra-hippocampal injection of BDNF inhibitor was significantly depressed and the expression of nNOS was significantly increased (P 〈 0.01). Intra-hippocampal injections of an nNOS inhibitor reversed the depression-like behavioral changes induced by CUMS or intra-hippocampal injection of BDNF inhibitor. CONCLUSION: CUMS induced a decrease in expression of BDNF and an increase in expression of NO in the hippocampus, which may lead to depression.展开更多
AIM To observe the nitric oxide synthase (NOS) distribution in the esophageal mucosa andhemodynamic changes in cirrhotic rats.METHODS NOS distribution in the loweresophagus of rats with carbon tetrachlorideinduced cir...AIM To observe the nitric oxide synthase (NOS) distribution in the esophageal mucosa andhemodynamic changes in cirrhotic rats.METHODS NOS distribution in the loweresophagus of rats with carbon tetrachlorideinduced cirrhosis was assessed by using NADPHdiaphorase (NADPH-d ) histochemical method.Concentration of NO in serum were measured byfluorometric assay. Mean arterial pressure(MAP), cardiac output (CO), cardiac index (CI),splanchnic vascular resistance (SVR ), andsplanchnic blood flow (SBF ) were alsodetermined using 5’CO-labeled microspheretechnique.RESULTS Intensity of NOS staining in theesophageal epithelium of cirrhotic rats wassignificantly stronger than that in controls.There was a NOS--positive staining area in theendothelia of esophageal submucosal vessels ofcirrhotic rats, but the NOS staining was negativein normal rats. NO concentration of serum incirrhotic rats were significantly higher incomparison with that of controls. Cirrhotic ratshad significantly lower MAP, SVR and higherSBF than those of the controls.CONCLUSION SPlanchnic hyperdynamiccirculatory state was observed in rats withcirrhosis. The endogenous NO may play animportant role in development of esophagealvarices and in changes of hemodynamics incirrhosis.展开更多
BACKGROUND: Varying degrees of inflammatory responses occur during lumbar nerve root compression. Studies have shown that nitric oxide synthase (NOS) and calcitonin gene-related peptide (CGRP) are involved in sec...BACKGROUND: Varying degrees of inflammatory responses occur during lumbar nerve root compression. Studies have shown that nitric oxide synthase (NOS) and calcitonin gene-related peptide (CGRP) are involved in secondary disc inflammation. OBJECTIVE: To observe the effects of warm acupuncture on the ultrastructure of inflammatory mediators in a rat model of lumbar nerve root compression, including NOS and CGRP contents. DESIGN, TIME AND SETTING: Randomized, controlled study, with molecular biological analysis, was performed at the Experimental Center, Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, between September 2006 and April 2007. MATERIALS: Acupuncture needles and refined Moxa grains were purchased from Shanghai Taicheng Technology Development Co., Ltd., China; Mobic tablets were purchased from Shanghai Boehringer Ingelheim Pharmaceuticals Co., Ltd., China; enzyme linked immunosorbent assay (ELISA) kits for NOS and CGRP were purchased from ADL Biotechnology, Inc., USA. METHODS: A total of 50, healthy, adult Sprague-Dawley rats, were randomly divided into five groups normal, model, warm acupuncture, acupuncture, and drug, with 10 rats in each group. Rats in the four groups, excluding the normal group, were used to establish models of lumbar nerve root compression. After 3 days, Jiaji points were set using reinforcing-reducing manipulation in the warm acupuncture group. Moxa grains were burned on each needle, with 2 grains each daily. The acupuncture group was the same as the warm acupuncture group, with the exception of non-moxibustion. Mobic suspension (3.75 mg/kg) was used in the oral drug group, once a day. Treatment of each group lasted for 14 consecutive days. Modeling and medication were not performed in the normal group. MAIN OUTCOME MEASURES: The ultrastructure of damaged nerve roots was observed with transmission electron microscopy; NOS and CGRP contents were measured using ELISA. RESULTS: The changes of the radicular ultramicrostructure were characterized by Wallerian degeneration; nerve fibers were clearly demyelinated; axons collapsed or degenerated; outer Schwann cell cytoplasm was swollen and its nucleus was compacted. Compared with the normal group, NOS and CGRP contents in the nerve root compression zone in the model group were significantly increased (P 〈 0.01). Nerve root edema was improved in the drug, acupuncture and the warm acupuncture groups over the model group. NOS and CGRP expressions were also decreased with the warm acupuncture group having the lowest concentration (P 〈 0.01). CONCLUSION: In comparison to the known effects of Mobic drug and acupuncture treatments, the warm acupuncture significantly decreased NOS and CGRP expression which helped improve the ultrastructure of the compressed nerve root.展开更多
3-hydroxy-3-methylgulutaryl-coenzyme A (HMG-CoA) reductase inhibitors or statins are a kind of lipid-lowering agents and have been used for the prevention and treatment of Cardiovascular diseases. Recent studies sug...3-hydroxy-3-methylgulutaryl-coenzyme A (HMG-CoA) reductase inhibitors or statins are a kind of lipid-lowering agents and have been used for the prevention and treatment of Cardiovascular diseases. Recent studies suggested that statins, besides lowering cholesterol, may protect vessels by enhancing the activity of endothelial nitric oxide synthase (eNOS). In the present study, we investigated if simvastatin increases eNOS activity through its phosphorylation in 293 cells (293-eNOS) with stable expression of eNOS. The results showed that incubation of 293-eNOS cells with simvastatin (10 μm/L) for 2 h significantly increased in the activity of eNOS as shown by the conversion of L-arginine to L-citrulline (2889.70±201.51 versus 5630.18+218.75 pmol/min . mg proteins) (P〈0.01). Western blotting revealed that simvastatin increased phosphorylation of eNOS at 1177 (ser) and also 495 (thr) but did not affect the overall expression of eNOS or inducible NOS. Further study found that simvastatin raised phosphorylation levels of Akt and AMPK, and such effect could be antagonized by Akt inhibitor or AMPK inhibitor. These results suggest that simvastatin could stimulate,the activity of eNOS via its phosphorylation by Akt and AMPK, which provides a new mechanism, other than lipid-lowering effect, for the cardiovascular protection of statins.展开更多
BACKGROUND: Nitric oxide (NO) and prostacyclin (PGI(2)) are both powerful vasoactive substances correlated with the hyperhemodynamics of portal hypertension (PHT), a common syndrome characterized by a pathological inc...BACKGROUND: Nitric oxide (NO) and prostacyclin (PGI(2)) are both powerful vasoactive substances correlated with the hyperhemodynamics of portal hypertension (PHT), a common syndrome characterized by a pathological increase in portal venous pressure. The purpose of the present study was to evaluate the possible interaction between these two endothelial vasodilators, together with their respective roles in the hyperdynamic splanchnic circulation of PHT. METHODS: Ninety-six male Sprague-Dawley rats were randomly divided into three groups: intrahepatic portal hypertension (IHPH) induced by injection of CCI4 (n=31), prehepatic portal hypertension (PHPH) induced by partial stenosis of the portal vein (n=33), and sham-operated controls (SO) (n=32). Animals of each group received indomethacin (INDO), a cyclooxygenase (COX) inhibitor, either short-term (7 days) or long-term (15 days), with saline as control. Free portal pressure (FPP), together with the concentration of NO and PGI(2) in serum were measured. The activity of constitutive nitric oxide synthase (cNOS) and inducible nitric oxide synthase (iNOS) in the abdominal aorta and small intestine were determined by spectrophotometry. RT-PCR was performed to measure the levels of cNOS and iNOS mRNA in the arteries and small intestines. RESULTS: Compared with SO rats, the concentrations of NO and PGI(2) in PHT rats were elevated, which were consistent with the increased FPP (P<0.05). Although administration of INDO persistently decreased the concentration of PGI(2) in serum (P<0.05), the long-term INDO-treated IHPH and PHPH groups had restored splanchnic hyperdynamic circulation, demonstrated by the enhanced FPP (P<0.05). Furthermore, the changes of dynamic circulatory state in both IHPH and PHPH rats were concomitant with the expression and activity of iNOS and the concentration of NO (P<0.05). Although the expression and activity of cNOS in abdominal aorta of PHT rats were higher than in SO rats (P<0.05), there was no difference in small intestinal tissues between PHT and SO rats (P>0.05). Moreover, the changes of iNOS activity and mRNA expression were more marked than cNOS in PHT rats, and there was no difference in expression and activity of cNOS between PHT rats treated by short- and long-term INDO (P>0.05). CONCLUSIONS: iNOS plays an important role in the hemodynamic abnormalities of PHT induced by overproduction of NO. There is a possible interaction between PGI(2) and NO in hyperbemodynamics of PHT, but PGI(2) may not be a mediator in the formation and development of the hyperdynamic circulatory state in PHT rats.展开更多
In order to investigate the role of nitric oxide(NO) in pathogenesis of hypoxic pulmonary hypertension(HPH), the mean pulmonary arterial pressure(mPAP), mRNA expression of NO synthase(NOS) in lung tissues, cGMP levels...In order to investigate the role of nitric oxide(NO) in pathogenesis of hypoxic pulmonary hypertension(HPH), the mean pulmonary arterial pressure(mPAP), mRNA expression of NO synthase(NOS) in lung tissues, cGMP levels, and their relationships were studied in rats exposed to hypoxia from 8 h to 28days. The results showed that mPAP began to increase in animals exposed to 10 % O2 for 8 h. Moreover, the longer the exposure, the higher the mPAP.Northern blot analysis and dot blot hybridization indicated that mRNA expression of NO in lung tissues of hypoxic rats tended to decrease with exposure days, but that of β-actin which acted as a control did not alter. The cGMP levels of plasma and lung tissues in hypoxic rats also inclined to be lower with exposure days. A marked negative correlations between the changes of cGMP levels and those of mPAP were found. It was suggested that mRNA expression of NOS gene was attenuated in hypoxic lung tissues, which may be one of important pathogenetic mechanisms of HPH.展开更多
The management of neurological disorders have huge and increasing human and economic costs. Despite this, there is a scarcity of effective therapeutics, and there is an extreme urgency for new and real treatments. In ...The management of neurological disorders have huge and increasing human and economic costs. Despite this, there is a scarcity of effective therapeutics, and there is an extreme urgency for new and real treatments. In this short review we analyze some promising advancements in the search of new bioactive molecules targeting neuronal nitric oxide synthase (nNOS), an enzyme deputed to the biosynthesis of nitric oxide (NO). In different conditions of neuronal damages, this molecule is overproduced, contributing to the pathogenesis and progression of neuronal diseases. Two main approaches to modulate nNOS are discussed: a first one consisting in the direct inhibition of the enzyme by means of small organic molecules, which can be also active against other different targets involved in such diseases. A second section is dedicated to molecules able to prevent the formation of the ternary complex N-methyl-D-aspartate (NMDA)type glutamate receptors, postsynaptic density-95 (PSD95) protein-nNOS, which is necessary to activate the latter for the biosynthesis of NO.展开更多
BACKGROUND: Previous studies have shown that extracellular signal-regulated kinase 1/2 (ERK1/2) and nitric oxide activation play a pivotal role in central sensitization and long-term neuronal plasticity induced by ...BACKGROUND: Previous studies have shown that extracellular signal-regulated kinase 1/2 (ERK1/2) and nitric oxide activation play a pivotal role in central sensitization and long-term neuronal plasticity induced by noxious stimulation. However, their effects on compressive neuralgia formation and maintenance remain poorly understood.OBJECTIVE: To investigate effects of the specific inhibitor of ERK1/2 signal pathway U0126 on neuronal nitric oxide synthase (nNOS) expression in the dorsal horn of the spinal cord in a compressive neuralgia rat model.DESIGN, TIME AND SETTING: A randomized, controlled experiment was performed at the Institute of Otolaryngology, Head and Neck Surgery, First Hospital of Jilin University from July 2008 to March 2009.MATERIALS: U0126 (Bio-Mol, USA) was used in this study.METHODS: A total of 84 rats were randomly assigned to two groups. In the first part of the experiment, 24 rats were used for behavioral testing, and they were randomly assigned to three sub-groups (n =8): U0126, dimethyl sulfoxide (DMSO) and model control. In the second part of the experiment, 60 rats were used for immunofluorescence and Western blot analysis, and they were randomly assigned to six sub-groups (n = 10): sham surgery, model control, U0126 post-injection at 0.5, 2, 12 and 24 hours. Neuropathic pain was produced by chronic compression to the dorsal root ganglion in rats from each sub-group. Rats in the U0126 group were administered a 5-ug U0126 intrathecal injection, and rats in the DMSO group were administered a 10-μL 5% DMSO intrathecal injection.MAIN OUTCOME MEASURES: Changes in mechanical and thermal hyperalgesia were observed using von Frey filaments and thermalqia stimular. Thermal and mechanical hyperalgesia were stimulated at different time points following intrathecal injection of U0126. nNOS activation and expression in the spinal cord dorsal horn were determined by immunofluorescence and Western blot analysis.RESULTS: Intrathecal injection of U0126 significantly attenuated chronic compression of dorsal root ganglion-induced mechanical and thermal hyperalgesia. Immunofluorescence staining results demonstrated that, compared to the sham surgery group, the number of nNOS-positive neurons was significantly increased in the injured spinal dorsal horn in the model control group (P〈0.01). However, compared to the model control group, there were significantly decreasing numbers of nNOS-positive neurons in the U0126 post-injection groups at 0.5-hour, 2-hour, and 12-hour (P〈0.05). Western blot analysis revealed similar results. CONCLUSION: Decreased activity in the ERK signal pathway resulted in down regulated nNOS expression in the dorsal horn of the spinal cord. These results suggested that ERK is involved in nitric oxide reaction to neuropathic pain.展开更多
The present study detected distribution and expression of nerve growth factor and inducible nitric oxide synthase in the mesencephalon and diencephalon, as well as visual- and auditory-related nervous tissues, in a ma...The present study detected distribution and expression of nerve growth factor and inducible nitric oxide synthase in the mesencephalon and diencephalon, as well as visual- and auditory-related nervous tissues, in a macaque model of type 2 diabetes using immunohistochemistry. Results showed that nerve growth factor expression decreased, but inducible nitric oxide synthase expression increased, in the mesencephalon and diencephalon, as well as visual- and auditory- related nervous tissues. These results suggested that nerve growth factor and inducible nitric oxide synthase play an important role in regulating the development of diabetic visual- and auditory-related diseases.展开更多
Alzheimer’s disease is a neurodegenerative disorder characterized by progressive cognitive impairment and neuropathology. Recent preclinical and epidemiological studies proposed statins as a possible therapeutic drug...Alzheimer’s disease is a neurodegenerative disorder characterized by progressive cognitive impairment and neuropathology. Recent preclinical and epidemiological studies proposed statins as a possible therapeutic drug for Alzheimer’s disease, but the exact mechanisms of action are still unknown. Biliverdin reductase-A is a pleiotropic enzyme involved in cellular stress responses. It not only transforms biliverdin-IX alpha into the antioxidant bilirubin-IX alpha but its serine/threonine/ tyrosine kinase activity is able to modulate cell signaling networks. We previously reported the beneficial effects of atorvastatin treatment on biliverdin reductase-A and heme oxygenase-1 in the brains of a well characterized pre-clinical model of Alzheimer’s disease, aged beagles, together with observed improvement in cognition. Here we extend our knowledge of the effects of atorvastatin on inducible nitric oxide synthase in parietal cortex, cerebellum and liver of the same animals. We demonstrated that atorvastatin treatment (80 mg/day for 14.5 months) to aged beagles selectively increased inducible nitric oxide synthase in the parietal cortex but not in the cerebellum. In contrast, inducible nitric oxide synthase protein levels were significantly decreased in the liver. Significant positive correlations were found between biliverdin reductase-A and inducible nitric oxide synthase as well as heme oxygenase-1 protein levels in the parietal cortex. The opposite was observed in the liver. Inducible nitric oxide synthase up-regulation in the parietal cortex was positively associated with improved biliverdin reductase-A functions, whereas the oxidative-induced impairment of biliverdin reductase-A in the liver negatively affected inducible nitric oxide synthase expression, thus suggesting a role for biliverdin reductase-A in atorvastatin-dependent inducible nitric oxide synthase changes. Interestingly, increased inducible nitric oxide synthase levels in the parietal cortex were not associated with higher oxidative/nitrosative stress levels. We hypothesize that biliverdin reductase-A-dependent inducible nitric oxide synthase regulation strongly contributes to the cognitive improvement observed following atorvastatin treatment.展开更多
The precise aetiology of benign prostatic hyperplasia (BPH) remains unclear; however, it is known that immunological inflammatory processes have a role in the pathogenesis of BPH initiation and progression. Nitric o...The precise aetiology of benign prostatic hyperplasia (BPH) remains unclear; however, it is known that immunological inflammatory processes have a role in the pathogenesis of BPH initiation and progression. Nitric oxide synthase 2 (NOS2) inducible expression is closely correlated with prostatic disease, including prostate cancer and BPH. The aim of this study was to investigate the relationship between NOS2 polymorphisms and BPH. With a cohort of 205 controls and 229 BPH subjects, we genotyped three single nucleotide polymorphisms (SNPs) in the NOS2 gene, including rs2779248 (promoter, -278 T/C), rs 10459953 (5'-untranslated region) and rs2297518 (exon 16, missense, Ser608Leu), using direct sequencing and restriction fragment length polymorphism. The genotypic and allelic frequencies between control and BPH subjects were compared, and the associations among the BPH subjects were analyzed. SNPStats, SNPAnalyzer and HelixTree programmes were used to analyze SNPs. There was no association on SNPs between control and BPH subjects. When BPH subjects were analyzed, there was no association on SNPs between the low and high prostate-specific antigen groups. However, one SNP (rs 10459953, odds ratio [OR] = 0.44, 95% confidence interval [CI] = 0.29-0.65, P 〈 0.0001, in codominant model; OR = 0.23, 95% CI = 0.12-0.46, P 〈 0.0001, in dominant model; and OR = 0.46, 95% CI = 0.24-0.86, P = 0.015, in recessive model) was associated with prostatic volume in BPH. We detected a strong association in genotype frequencies of NOS2 SNP (rs10459953) between subjects with small and large prostatic volume in BPH. The result suggests that NOS2 may be associated with prostatic volume in BPH.展开更多
文摘To investigate the effects of ischemia-reperfusion on the levels of nitric oxide and nitric oxide synthasc isoforms (nNOS and iNOS), rat organotypic hippocampus slice were cultured in vitro and subjected to ischemia by oxygen glucose deprivation (OGD) for 30 min and then placed in the normal culture condition. The ischemia-reperfusion produced a time-dependent increase in nitrite levels in the culture medium. Reverse transcriptional-polymerase chain reaction showed augmented levels of mRNA for both nNOS and iNOS when compared with control at 12 h and remained increase at 36 h after OGD (P〈0.05). The protein levels of both nitric oxide synthase isoforms increased significantly as determined by Western Blot. OGD also caused neurotoxicity in this model as revealed by the elevated lactate dehydrogenase (LDH) efflux into the incubation solution. The resuits suggest that organotypic hippocampus slice is a useful model in studying ischemia-reperfusion brain injury. NO and NOS may play a critical role in the ischemia-reperfusion brain damage in vitro.
基金supported by the National Key R&D Program of China,No.2019YFE0121200(to LQZ)the National Natural Science Foundation of China,Nos.82325017(to LQZ),82030032(to LQZ),82261138555(to DL)+2 种基金the Natural Science Foundation of Hubei Province,No.2022CFA004(to LQZ)the Natural Science Foundation of Jiangxi Province,No.20224BAB206040(to XZ)Research Project of Cognitive Science and Transdisciplinary Studies Center of Jiangxi Province,No.RZYB202201(to XZ).
文摘With an increase in global aging,the number of people affected by cerebrovascular diseases is also increasing,and the incidence of vascular dementia-closely related to cerebrovascular risk-is increasing at an epidemic rate.However,few therapeutic options exist that can markedly improve the cognitive impairment and prognosis of vascular dementia patients.Similarly in Alzheimer’s disease and other neurological disorders,synaptic dysfunction is recognized as the main reason for cognitive decline.Nitric oxide is one of the ubiquitous gaseous cellular messengers involved in multiple physiological and pathological processes of the central nervous system.Recently,nitric oxide has been implicated in regulating synaptic plasticity and plays an important role in the pathogenesis of vascular dementia.This review introduces in detail the emerging role of nitric oxide in physiological and pathological states of vascular dementia and summarizes the diverse effects of nitric oxide on different aspects of synaptic dysfunction,neuroinflammation,oxidative stress,and blood-brain barrier dysfunction that underlie the progress of vascular dementia.Additionally,we propose that targeting the nitric oxide-sGC-cGMP pathway using certain specific approaches may provide a novel therapeutic strategy for vascular dementia.
基金supported by the Natural Science Foundation of ChinaNos.81971212 (to FG)+7 种基金81601129 (to XXX)the Open Fund of the Key Laboratory of Medical ElectrophysiologyMinistry of Education&Medical Electrophysiological Key Laboratory of Sichuan ProvinceInstitute of Cardiovascular ResearchSouthwest Medical UniversityNo.KeyME-2018-07 (to FG)Liaoning Province Xingliao Talent Program ProjectNo.XLYC1907164 (to FG)
文摘Dysfunction of neuronal nitric oxide synthase contributes to neurotoxicity,which triggers cell death in various neuropathological diseases,including epilepsy.Studies have shown that inhibition of neuronal nitric oxide synthase activity increases the epilepsy threshold,that is,has an anticonvulsant effect.However,the exact role and potential mechanism of neuronal nitric oxide synthase in seizures are still unclear.In this study,we performed RNA sequencing,functional enrichment analysis,and weighted gene coexpression network analysis of the hippocampus of tremor rats,a rat model of genetic epilepsy.We found damaged hippocampal mitochondria and abnormal succinate dehydrogenase level and Na+-K+-ATPase activity.In addition,we used a pilocarpine-induced N2a cell model to mimic epileptic injury.After application of neuronal nitric oxide synthase inhibitor 7-nitroindazole,changes in malondialdehyde,lactate dehydrogenase and superoxide dismutase,which are associated with oxidative stress,were reversed,and the increase in reactive oxygen species level was reversed by 7-nitroindazole or reactive oxygen species inhibitor N-acetylcysteine.Application of 7-nitroindazole or N-acetylcysteine downregulated the expression of caspase-3 and cytochrome c and reversed the apoptosis of epileptic cells.Furthermore,7-nitroindazole or N-acetylcysteine downregulated the abnormally high expression of NLRP3,gasdermin-D,interleukin-1βand interleukin-18.This indicated that 7-nitroindazole and N-acetylcysteine each reversed epileptic cell death.Taken together,our findings suggest that the neuronal nitric oxide synthase/reactive oxygen species pathway is involved in pyroptosis of epileptic cells,and inhibiting neuronal nitric oxide synthase activity or its induced oxidative stress may play a neuroprotective role in epilepsy.
基金supported by the Natural Nature Science Foundation of China,Nos.82030071,81874004the Science and Technology Major Project of Changsha,No.kh2103008(all to JZH).
文摘Treatment with metformin can lead to the recovery of pleiotropic biological activities after spinal cord injury.However,its effect on spinal cord injury in aged mice remains unclear.Considering the essential role of angiogenesis during the regeneration process,we hypothesized that metformin activates the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway in endothelial cells,thereby promoting microvascular regeneration in aged mice after spinal cord injury.In this study,we established young and aged mouse models of contusive spinal cord injury using a modified Allen method.We found that aging hindered the recovery of neurological function and the formation of blood vessels in the spinal cord.Treatment with metformin promoted spinal cord microvascular endothelial cell migration and blood vessel formation in vitro.Furthermore,intraperitoneal injection of metformin in an in vivo model promoted endothelial cell proliferation and increased the density of new blood vessels in the spinal cord,thereby improving neurological function.The role of metformin was reversed by compound C,an adenosine monophosphate-activated protein kinase inhibitor,both in vivo and in vitro,suggesting that the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway likely regulates metformin-mediated angiogenesis after spinal cord injury.These findings suggest that metformin promotes vascular regeneration in the injured spinal cord by activating the adenosine monophosphate-activated protein kinase/endothelial nitric oxide synthase pathway,thereby improving the neurological function of aged mice after spinal cord injury.
文摘Background Exposure of adult mice to more than 95% O_2 produces a lethal injury by 72 hours. Nitric oxide synthase (NOS) is thought to contribute to the pathophysiology of murine hyperoxia-induced acute lung injury (ALI). Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages. OPN inhibits inducible nitric oxide synthase (iNOS), which generates large amounts of nitric oxide production. However, the relationship between nitric oxide and endogenous OPN in lung tissue during hyperoxia-induced ALI has not yet been elucidated, thus we examined the role that OPN plays in the hyperoxia-induced lung injury and its relationships with NOS.Methods One hundred and forty-four osteopontin knock-out (KO) mice and their matched wild type background control (WT) were exposed in sealed cages 〉95% oxygen or room air for 24-72 hours, and the severity of lung injury was assessed; expression of OPN, endothelial nitric oxide synthase (eNOS) and iNOS mRNA in lung tissues at 24,48 and 72 hours of hyperoxia were studied by reverse transcription-polymerase chain reaction (RT-PCR); immunohistochemistry (IHC) was performed for the detection of iNOS, eNOS, and OPN protein in lung tissues.Results OPN KO mice developed more severe acute lung injury at 72 hours of hyperoxia. The wet/dry weight ratio increased to 6.85±0.66 in the KO mice at 72 hours of hyperoxia as compared to 5.31±0.92 in the WT group (P〈0.05). iNOS mRNA (48 hours: 1.04±0.08 vs. 0.63±0.09, P〈0.01; 72 hours: 0.89±0.08 vs. 0.72±0.09, P〈0.05) and eNOS mRNA (48 hours: 0.62±0.08 vs. 0.43±0.09, P〈0.05; 72 hours: 0.67±0.08 vs. 0.45±0.09, P〈0.05) expression was more significantly increased in OPN KO mice than their matched WT mice when exposed to hyperoxia. IHC study showed higher expression of iNOS (20.54±3.18 vs. 12.52±2.46, P 〈0.05) and eNOS (19.83±5.64 vs. 9.45±3.82, P 〈0.05) in lung tissues of OPN KO mice at 72 hours of hyperoxia. Conclusion OPN can protect against hyperoxia-induced lung injury by inhibiting NOS.
基金supported by the Natural Science Foundation of Shandong Province(No.ZR2020QC214)the Young Experts of Taishan Scholars(No.tsqn201909130)+3 种基金the Science and Technology Support Plan for Youth Innovation of Colleges and Universities in Shandong Province(No.2019KJF003)the‘First Class Fishery Discipline’Programme in Shandong Provincea special talent programme‘One Thing One Decision(YishiYiyi)’Programme in Shandong Province,Chinathe Breeding Plan of Shandong Provincial Qingchuang Research Team(2019)。
文摘Neuronal nitric oxide synthase(nNOS)was the producer of nitric oxide(NO)which played important gas messenger molecules in biological process.It also can take effect as immune regulation molecule in organism.Black rockfish(Sebastes schlegelii)is an important economic fish which were widely farmed in East Asia countries.Meanwhile,the pathogenic bacteria such as the Edwardsiella tarda and Vibrio anguillarum in seawater always brought serious obstacles to their healthy growth.In order to explore the expression pattern of n NOS gene under the pathogen stimulation and predict its immune function,the n NOS gene in black rockfish named Ssn NOS was identified.It was 3780 bp in length,located on chromosome 6,and contained 27 coding domain sequence(CDs).According to the phylogenetic analysis,the Ssn NOS showed closest relative to the counterpart gene of swamp eel(Monopterus albus).Meanwhile,analysis of Ssn NOS expression in various healthy tissues showed that Ssn NOS expression level was highest in healthy brain tissues,followed by intestinal tissues.In addition,Ssn NOS showed significant expression changes in response to stimulation by two pathogens.Particular in gill,the expression of Ssn NOS after pathogenic stimulation increased significantly.The Elisa analysis showed the Ssn NOS content in gills was much higher than that in other tissues at all time points.Moreover,the expression patterns of Ssn NOS in brain,intestine and kidney after stimulation by pathogens showed a distinct expression pattern which first down-regulated and then up-regulated.Therefore,the Ssn NOS may be an important signaling molecule for fish to respond rapidly in immune stimulation.
文摘Objective: To investigate the differen t expression of three isozymes of nitric oxide synthase (NOS) in diabetic rat colo ns and the contribution to the colonic dysfunction. Methods: Sprague-Dawley (SD) rats were used in this experiment and diabetes were induc ed by streptozotocin (65 mg/kg, i.v.). Three isozymes of NOS (nNOS, iNOS and eNO S) expression in proximal and distal colon were measured in two weeks after diab etes induction using the methods of immunocytochemistry and semi-quantitative r everse transcription-polymerase chain reaction (RT-PCR). Results: Positive immunoreactivity for nNOS was found in intermuscular and submucous plexus neuronal cells, neither eNOS nor iNOS had been found in any layers of col on in the two groups. The expression of nNOS mRNA was significantly increased in diabetic colon than that in control rats as determined by RT-PCR. The eNOS mRN A level of diabetic colon was lower compared to thecontrol rats, while no expres sion of iNOS mRNA was found in the normal or diabetic rats. Conclusion: This report has demonstrated that nNOS increased and eNOS decreased in rat colon in the early stages of diabetes. NO production by the nNOS might play a key role in colonic dysfunction, as supported by raised nNOS mRNA and enzyme e xpression in the diabetic colon. Reduced eNOS activity might also contribute to colonic dysfunction in experimental diabetes.
基金The authors would like to acknowledge the National Nature Science Foundation of China(No.30070927)Beijing National Nature Science Foundation(No.7012023)for grants for this work.
文摘Aim: To investigate the effect of icariin on erectile function and the expression of nitric oxide synthase (NOS) isoforms in castrated rats. Methods: Thirty-two adult male Wistar rats were randomly divided into one shamoperated group (A) and three castrated groups (B, C and D). One week after surgery, rats were treated with normal saline (groups A and B) or oral icariin (1 mg/[kg·day] for group C and 5 mg/[kg·day] for group D) for 4 weeks. One week after treatment, the erectile function of the rats was assessed by measuring intracavernosal pressure (ICP) during electrostimulation of the cavernosal nerve. The serum testosterone (ST) levels, the percent of smooth muscle (PSM) in trabecular tissue, and the expression of mRNA and proteins of neuronal nitric oxide synthase (nNOS), inducible nitric oxide synthase (iNOS), endothelial nitric oxide synthase (eNOS) and phosphodiesterase V (PDES) in corpus cavernosum (CC) were also evaluated. Results: ICP, PSM, ST and the expression of nNOS, iNOS, eNOS and PDE5 were significantly decreased in group B compared with those in group A (P 〈 0.01). However, ICE PSM and the expression of nNOS and iNOS were increased in groups C and D compared with those in group B (P 〈 0.05). Changes in ST and the expression of eNOS and PDE5 were not significant (P 〉 0.05) in groups C and D compared with those in group B. Conclusion: Oral treatment with icariin (〉 98.6 % purity) for 4 weeks potentially improves erectile function. This effect is correlated with an increase in PSM and the expression of certain NOS in the CC of castrated rats. These results suggest that icariin may have a therapeutic effect on erectile dysfunction.
基金the grant from Natural Foundation of Shaanxi Province, No.2006C240
文摘BACKGROUND: Accumulated evidence indicates an important role for hippocampal dendrite atrophy in development of depression, while brain-derived neurotrophic factor (BDNF) participates in hippocampal dendrite growth. OBJECTIVE: To discuss the role of BDNF and neuronal nitric oxide synthase (nNOS) in chronic and unpredictable stress-induced depression and the pathogenesis of depression. DESIGN, TIME AND SETTING: Randomized, controlled animal experiment. The experiment was carded out from October 2006 to May 2007 at the Department of Animal Physiology, College of Life Science, Shaanxi Normal University. MATERIALS: Thirty-seven male Sprague-Dawley rats weighing 250-300 g at the beginning of the experiment were obtained from Shaanxi Provincial Institute of Traditional Chinese Medicine (Xi'an, China). BDNF antibody and nNOS antibody were provided by Santa Cruz (USA). K252a (BDNF inhibitor) and 7-NI (nNOS inhibitor) were provided by Sigma (USA). METHODS: Animals were randomly divided into five groups: Control group, chronic unpredicted mild stress (CUMS) group, K252a group, K252a+7-NI group and 7-NI+CUMS group. While the Control, K252a and K252a+7-NI groups of rats not subjected to stress had free access to food and water, other groups of rats were subjected to nine stressors randomly applied for 21 days, with each stressor applied 2-3 times. On days 1, 7, 14 and 21 during CUMS, rats received microinjection of 1 μL of physiological saline in the Control and CUMS groups, 1 ~ L of K252a in the K252a group, 1 μL of K252a and 7-NI in the K252a+7-NI group, and 1 μL of 7-NI in the 7-NI+CUMS group. We observed a variety of alterations in sucrose preference, body weight change, open field test and forced swimming test, and observed the expression of BDNF and nNOS in rat hippocampus by immunohistochemistry; MAIN OUTCOME MEASURES: ① A variety.of behavioral alterations of rats; ② The expression of BDNF and nNOS in rat hippocampus. RESULTS: Compared with the Control group, the behavior of the CUMS rats was significantly depressed, the expression of BDNF decreased (P 〈 0.01) but the expression of nNOS increased (P 〈 0.01). The behavior of rats given intra-hippocampal injection of BDNF inhibitor was significantly depressed and the expression of nNOS was significantly increased (P 〈 0.01). Intra-hippocampal injections of an nNOS inhibitor reversed the depression-like behavioral changes induced by CUMS or intra-hippocampal injection of BDNF inhibitor. CONCLUSION: CUMS induced a decrease in expression of BDNF and an increase in expression of NO in the hippocampus, which may lead to depression.
文摘AIM To observe the nitric oxide synthase (NOS) distribution in the esophageal mucosa andhemodynamic changes in cirrhotic rats.METHODS NOS distribution in the loweresophagus of rats with carbon tetrachlorideinduced cirrhosis was assessed by using NADPHdiaphorase (NADPH-d ) histochemical method.Concentration of NO in serum were measured byfluorometric assay. Mean arterial pressure(MAP), cardiac output (CO), cardiac index (CI),splanchnic vascular resistance (SVR ), andsplanchnic blood flow (SBF ) were alsodetermined using 5’CO-labeled microspheretechnique.RESULTS Intensity of NOS staining in theesophageal epithelium of cirrhotic rats wassignificantly stronger than that in controls.There was a NOS--positive staining area in theendothelia of esophageal submucosal vessels ofcirrhotic rats, but the NOS staining was negativein normal rats. NO concentration of serum incirrhotic rats were significantly higher incomparison with that of controls. Cirrhotic ratshad significantly lower MAP, SVR and higherSBF than those of the controls.CONCLUSION SPlanchnic hyperdynamiccirculatory state was observed in rats withcirrhosis. The endogenous NO may play animportant role in development of esophagealvarices and in changes of hemodynamics incirrhosis.
基金Modern Projects of Traditional Chinese Medicine of Shanghai Science and Technology Commission, No.08DZ1973200Research Projects of Shanghai Bureau of Public Health,No.2006Q004L
文摘BACKGROUND: Varying degrees of inflammatory responses occur during lumbar nerve root compression. Studies have shown that nitric oxide synthase (NOS) and calcitonin gene-related peptide (CGRP) are involved in secondary disc inflammation. OBJECTIVE: To observe the effects of warm acupuncture on the ultrastructure of inflammatory mediators in a rat model of lumbar nerve root compression, including NOS and CGRP contents. DESIGN, TIME AND SETTING: Randomized, controlled study, with molecular biological analysis, was performed at the Experimental Center, Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, between September 2006 and April 2007. MATERIALS: Acupuncture needles and refined Moxa grains were purchased from Shanghai Taicheng Technology Development Co., Ltd., China; Mobic tablets were purchased from Shanghai Boehringer Ingelheim Pharmaceuticals Co., Ltd., China; enzyme linked immunosorbent assay (ELISA) kits for NOS and CGRP were purchased from ADL Biotechnology, Inc., USA. METHODS: A total of 50, healthy, adult Sprague-Dawley rats, were randomly divided into five groups normal, model, warm acupuncture, acupuncture, and drug, with 10 rats in each group. Rats in the four groups, excluding the normal group, were used to establish models of lumbar nerve root compression. After 3 days, Jiaji points were set using reinforcing-reducing manipulation in the warm acupuncture group. Moxa grains were burned on each needle, with 2 grains each daily. The acupuncture group was the same as the warm acupuncture group, with the exception of non-moxibustion. Mobic suspension (3.75 mg/kg) was used in the oral drug group, once a day. Treatment of each group lasted for 14 consecutive days. Modeling and medication were not performed in the normal group. MAIN OUTCOME MEASURES: The ultrastructure of damaged nerve roots was observed with transmission electron microscopy; NOS and CGRP contents were measured using ELISA. RESULTS: The changes of the radicular ultramicrostructure were characterized by Wallerian degeneration; nerve fibers were clearly demyelinated; axons collapsed or degenerated; outer Schwann cell cytoplasm was swollen and its nucleus was compacted. Compared with the normal group, NOS and CGRP contents in the nerve root compression zone in the model group were significantly increased (P 〈 0.01). Nerve root edema was improved in the drug, acupuncture and the warm acupuncture groups over the model group. NOS and CGRP expressions were also decreased with the warm acupuncture group having the lowest concentration (P 〈 0.01). CONCLUSION: In comparison to the known effects of Mobic drug and acupuncture treatments, the warm acupuncture significantly decreased NOS and CGRP expression which helped improve the ultrastructure of the compressed nerve root.
基金supported by grants from National Natural Sciences Foundation of China (No. 30430320 and 30770882)National 973 Project (No. 2007CB512004)
文摘3-hydroxy-3-methylgulutaryl-coenzyme A (HMG-CoA) reductase inhibitors or statins are a kind of lipid-lowering agents and have been used for the prevention and treatment of Cardiovascular diseases. Recent studies suggested that statins, besides lowering cholesterol, may protect vessels by enhancing the activity of endothelial nitric oxide synthase (eNOS). In the present study, we investigated if simvastatin increases eNOS activity through its phosphorylation in 293 cells (293-eNOS) with stable expression of eNOS. The results showed that incubation of 293-eNOS cells with simvastatin (10 μm/L) for 2 h significantly increased in the activity of eNOS as shown by the conversion of L-arginine to L-citrulline (2889.70±201.51 versus 5630.18+218.75 pmol/min . mg proteins) (P〈0.01). Western blotting revealed that simvastatin increased phosphorylation of eNOS at 1177 (ser) and also 495 (thr) but did not affect the overall expression of eNOS or inducible NOS. Further study found that simvastatin raised phosphorylation levels of Akt and AMPK, and such effect could be antagonized by Akt inhibitor or AMPK inhibitor. These results suggest that simvastatin could stimulate,the activity of eNOS via its phosphorylation by Akt and AMPK, which provides a new mechanism, other than lipid-lowering effect, for the cardiovascular protection of statins.
基金a grant from the KeyBasic Research Program of Shanghai(No.034119922)
文摘BACKGROUND: Nitric oxide (NO) and prostacyclin (PGI(2)) are both powerful vasoactive substances correlated with the hyperhemodynamics of portal hypertension (PHT), a common syndrome characterized by a pathological increase in portal venous pressure. The purpose of the present study was to evaluate the possible interaction between these two endothelial vasodilators, together with their respective roles in the hyperdynamic splanchnic circulation of PHT. METHODS: Ninety-six male Sprague-Dawley rats were randomly divided into three groups: intrahepatic portal hypertension (IHPH) induced by injection of CCI4 (n=31), prehepatic portal hypertension (PHPH) induced by partial stenosis of the portal vein (n=33), and sham-operated controls (SO) (n=32). Animals of each group received indomethacin (INDO), a cyclooxygenase (COX) inhibitor, either short-term (7 days) or long-term (15 days), with saline as control. Free portal pressure (FPP), together with the concentration of NO and PGI(2) in serum were measured. The activity of constitutive nitric oxide synthase (cNOS) and inducible nitric oxide synthase (iNOS) in the abdominal aorta and small intestine were determined by spectrophotometry. RT-PCR was performed to measure the levels of cNOS and iNOS mRNA in the arteries and small intestines. RESULTS: Compared with SO rats, the concentrations of NO and PGI(2) in PHT rats were elevated, which were consistent with the increased FPP (P<0.05). Although administration of INDO persistently decreased the concentration of PGI(2) in serum (P<0.05), the long-term INDO-treated IHPH and PHPH groups had restored splanchnic hyperdynamic circulation, demonstrated by the enhanced FPP (P<0.05). Furthermore, the changes of dynamic circulatory state in both IHPH and PHPH rats were concomitant with the expression and activity of iNOS and the concentration of NO (P<0.05). Although the expression and activity of cNOS in abdominal aorta of PHT rats were higher than in SO rats (P<0.05), there was no difference in small intestinal tissues between PHT and SO rats (P>0.05). Moreover, the changes of iNOS activity and mRNA expression were more marked than cNOS in PHT rats, and there was no difference in expression and activity of cNOS between PHT rats treated by short- and long-term INDO (P>0.05). CONCLUSIONS: iNOS plays an important role in the hemodynamic abnormalities of PHT induced by overproduction of NO. There is a possible interaction between PGI(2) and NO in hyperbemodynamics of PHT, but PGI(2) may not be a mediator in the formation and development of the hyperdynamic circulatory state in PHT rats.
文摘In order to investigate the role of nitric oxide(NO) in pathogenesis of hypoxic pulmonary hypertension(HPH), the mean pulmonary arterial pressure(mPAP), mRNA expression of NO synthase(NOS) in lung tissues, cGMP levels, and their relationships were studied in rats exposed to hypoxia from 8 h to 28days. The results showed that mPAP began to increase in animals exposed to 10 % O2 for 8 h. Moreover, the longer the exposure, the higher the mPAP.Northern blot analysis and dot blot hybridization indicated that mRNA expression of NO in lung tissues of hypoxic rats tended to decrease with exposure days, but that of β-actin which acted as a control did not alter. The cGMP levels of plasma and lung tissues in hypoxic rats also inclined to be lower with exposure days. A marked negative correlations between the changes of cGMP levels and those of mPAP were found. It was suggested that mRNA expression of NOS gene was attenuated in hypoxic lung tissues, which may be one of important pathogenetic mechanisms of HPH.
文摘The management of neurological disorders have huge and increasing human and economic costs. Despite this, there is a scarcity of effective therapeutics, and there is an extreme urgency for new and real treatments. In this short review we analyze some promising advancements in the search of new bioactive molecules targeting neuronal nitric oxide synthase (nNOS), an enzyme deputed to the biosynthesis of nitric oxide (NO). In different conditions of neuronal damages, this molecule is overproduced, contributing to the pathogenesis and progression of neuronal diseases. Two main approaches to modulate nNOS are discussed: a first one consisting in the direct inhibition of the enzyme by means of small organic molecules, which can be also active against other different targets involved in such diseases. A second section is dedicated to molecules able to prevent the formation of the ternary complex N-methyl-D-aspartate (NMDA)type glutamate receptors, postsynaptic density-95 (PSD95) protein-nNOS, which is necessary to activate the latter for the biosynthesis of NO.
基金Science and Technology Development Project Program of Jilin Province,China,No. 200505195
文摘BACKGROUND: Previous studies have shown that extracellular signal-regulated kinase 1/2 (ERK1/2) and nitric oxide activation play a pivotal role in central sensitization and long-term neuronal plasticity induced by noxious stimulation. However, their effects on compressive neuralgia formation and maintenance remain poorly understood.OBJECTIVE: To investigate effects of the specific inhibitor of ERK1/2 signal pathway U0126 on neuronal nitric oxide synthase (nNOS) expression in the dorsal horn of the spinal cord in a compressive neuralgia rat model.DESIGN, TIME AND SETTING: A randomized, controlled experiment was performed at the Institute of Otolaryngology, Head and Neck Surgery, First Hospital of Jilin University from July 2008 to March 2009.MATERIALS: U0126 (Bio-Mol, USA) was used in this study.METHODS: A total of 84 rats were randomly assigned to two groups. In the first part of the experiment, 24 rats were used for behavioral testing, and they were randomly assigned to three sub-groups (n =8): U0126, dimethyl sulfoxide (DMSO) and model control. In the second part of the experiment, 60 rats were used for immunofluorescence and Western blot analysis, and they were randomly assigned to six sub-groups (n = 10): sham surgery, model control, U0126 post-injection at 0.5, 2, 12 and 24 hours. Neuropathic pain was produced by chronic compression to the dorsal root ganglion in rats from each sub-group. Rats in the U0126 group were administered a 5-ug U0126 intrathecal injection, and rats in the DMSO group were administered a 10-μL 5% DMSO intrathecal injection.MAIN OUTCOME MEASURES: Changes in mechanical and thermal hyperalgesia were observed using von Frey filaments and thermalqia stimular. Thermal and mechanical hyperalgesia were stimulated at different time points following intrathecal injection of U0126. nNOS activation and expression in the spinal cord dorsal horn were determined by immunofluorescence and Western blot analysis.RESULTS: Intrathecal injection of U0126 significantly attenuated chronic compression of dorsal root ganglion-induced mechanical and thermal hyperalgesia. Immunofluorescence staining results demonstrated that, compared to the sham surgery group, the number of nNOS-positive neurons was significantly increased in the injured spinal dorsal horn in the model control group (P〈0.01). However, compared to the model control group, there were significantly decreasing numbers of nNOS-positive neurons in the U0126 post-injection groups at 0.5-hour, 2-hour, and 12-hour (P〈0.05). Western blot analysis revealed similar results. CONCLUSION: Decreased activity in the ERK signal pathway resulted in down regulated nNOS expression in the dorsal horn of the spinal cord. These results suggested that ERK is involved in nitric oxide reaction to neuropathic pain.
基金supported by the Program for Changjiang Scholars and Innovative Research Teaming University, No. IRT0848Sichuan Province International Technology Cooperation and Communication Research Programs, No. 2010HH0013+2 种基金Sichuan Province Basic Research Program, No. 2011JY0054the National Key Research Program of China, No. 2011ZX09301-001, 2011ZX09307-301-3Science and Technology Support Programs of Sichuan Province, No. 2011JO0040, 2011ZO0034
文摘The present study detected distribution and expression of nerve growth factor and inducible nitric oxide synthase in the mesencephalon and diencephalon, as well as visual- and auditory-related nervous tissues, in a macaque model of type 2 diabetes using immunohistochemistry. Results showed that nerve growth factor expression decreased, but inducible nitric oxide synthase expression increased, in the mesencephalon and diencephalon, as well as visual- and auditory- related nervous tissues. These results suggested that nerve growth factor and inducible nitric oxide synthase play an important role in regulating the development of diabetic visual- and auditory-related diseases.
基金Funding for the canine atorvastatin study was through the Alzheimer's Association IIRG-03-5673 to Elizabeth Head
文摘Alzheimer’s disease is a neurodegenerative disorder characterized by progressive cognitive impairment and neuropathology. Recent preclinical and epidemiological studies proposed statins as a possible therapeutic drug for Alzheimer’s disease, but the exact mechanisms of action are still unknown. Biliverdin reductase-A is a pleiotropic enzyme involved in cellular stress responses. It not only transforms biliverdin-IX alpha into the antioxidant bilirubin-IX alpha but its serine/threonine/ tyrosine kinase activity is able to modulate cell signaling networks. We previously reported the beneficial effects of atorvastatin treatment on biliverdin reductase-A and heme oxygenase-1 in the brains of a well characterized pre-clinical model of Alzheimer’s disease, aged beagles, together with observed improvement in cognition. Here we extend our knowledge of the effects of atorvastatin on inducible nitric oxide synthase in parietal cortex, cerebellum and liver of the same animals. We demonstrated that atorvastatin treatment (80 mg/day for 14.5 months) to aged beagles selectively increased inducible nitric oxide synthase in the parietal cortex but not in the cerebellum. In contrast, inducible nitric oxide synthase protein levels were significantly decreased in the liver. Significant positive correlations were found between biliverdin reductase-A and inducible nitric oxide synthase as well as heme oxygenase-1 protein levels in the parietal cortex. The opposite was observed in the liver. Inducible nitric oxide synthase up-regulation in the parietal cortex was positively associated with improved biliverdin reductase-A functions, whereas the oxidative-induced impairment of biliverdin reductase-A in the liver negatively affected inducible nitric oxide synthase expression, thus suggesting a role for biliverdin reductase-A in atorvastatin-dependent inducible nitric oxide synthase changes. Interestingly, increased inducible nitric oxide synthase levels in the parietal cortex were not associated with higher oxidative/nitrosative stress levels. We hypothesize that biliverdin reductase-A-dependent inducible nitric oxide synthase regulation strongly contributes to the cognitive improvement observed following atorvastatin treatment.
文摘The precise aetiology of benign prostatic hyperplasia (BPH) remains unclear; however, it is known that immunological inflammatory processes have a role in the pathogenesis of BPH initiation and progression. Nitric oxide synthase 2 (NOS2) inducible expression is closely correlated with prostatic disease, including prostate cancer and BPH. The aim of this study was to investigate the relationship between NOS2 polymorphisms and BPH. With a cohort of 205 controls and 229 BPH subjects, we genotyped three single nucleotide polymorphisms (SNPs) in the NOS2 gene, including rs2779248 (promoter, -278 T/C), rs 10459953 (5'-untranslated region) and rs2297518 (exon 16, missense, Ser608Leu), using direct sequencing and restriction fragment length polymorphism. The genotypic and allelic frequencies between control and BPH subjects were compared, and the associations among the BPH subjects were analyzed. SNPStats, SNPAnalyzer and HelixTree programmes were used to analyze SNPs. There was no association on SNPs between control and BPH subjects. When BPH subjects were analyzed, there was no association on SNPs between the low and high prostate-specific antigen groups. However, one SNP (rs 10459953, odds ratio [OR] = 0.44, 95% confidence interval [CI] = 0.29-0.65, P 〈 0.0001, in codominant model; OR = 0.23, 95% CI = 0.12-0.46, P 〈 0.0001, in dominant model; and OR = 0.46, 95% CI = 0.24-0.86, P = 0.015, in recessive model) was associated with prostatic volume in BPH. We detected a strong association in genotype frequencies of NOS2 SNP (rs10459953) between subjects with small and large prostatic volume in BPH. The result suggests that NOS2 may be associated with prostatic volume in BPH.