Effects of L-Tetrahydropalmatine on Energy Metabolism,Endothelin-1 and NO during Acute Cerebral Ischemia-reperfusion of Rats

To investigate the effects of L-tetrahydropalmatine (L-THP) on ener-gy metabolism, endothelin-1 (ET-1 ) and NO during acute cerebral ischemia-reperfusion of rats, 24 Wistar rats were randomly divided into four groups, with 6rats in each group: sham-operation group, simple ischemia group, ischemia-reperfusion group and treatment group (L-THP group). Cerebral ATP, lactate,ET-1 and NO levels were measured in all groups. Our results showed that treat-ment with L-THP could increase cerebral ATP levels, but decrease cerebral lac-tate, ET-1 and NO concentrations during ischemia-reperfusion in the treatmentgroup. It is concluded that L-THP could improve cerebral energy metabolism and protect the injured brain tissue, the mechanism of which might be related to suppression of overproduction of ET-1 and NO.

Taurine protects against retinal and optic nerve damage induced by endothelin-1 in rats via antioxidant effects

Endothelin-1（ET-1）, a potent vasoconstrictor, is involved in retinal vascular dysregulation and oxidative stress in glaucomatous eyes. Taurine（TAU）, a naturally occurring free amino acid, is known for its neuroprotective and antioxidant properties. Hence, we evaluated its neuroprotective properties against ET-1 induced retinal and optic nerve damage. ET-1 was administered intravitreally to Sprague-Dawley rats and TAU was injected as pre-, co-or post-treatment. Animals were euthanized seven days post TAU injection. Retinae and optic nerve were examined for morphology, and were also processed for caspase-3 immunostaining. Retinal redox status was estimated by measuring retinal superoxide dismutase, catalase, glutathione, and malondialdehyde levels using enzyme-linked immuosorbent assay. Histopathological examination showed significantly improved retinal and optic nerve morphology in TAU-treated groups. Morphometric examination showed that TAU pre-treatment provided marked protection against ET-1 induced damage to retina and optic nerve. In accordance with the morphological observations, immunostaining for caspase showed a significantly lesser number of apoptotic retinal cells in the TAU pre-treatment group. The retinal oxidative stress was reduced in all TAU-treated groups, and particularly in the pre-treatment group. The findings suggest that treatment with TAU, particularly pre-treatment, prevents apoptosis of retinal cells induced by ET-1 and hence prevents the changes in the morphology of retina and optic nerve. The protective effect of TAU against ET-1 induced retinal and optic nerve damage is associated with reduced retinal oxidative stress.

Effect of acupuncture on the genetic expression of myocardial endothelin-1 and atrial natriuretic peptide in rats with stress-induced prehypertension

Objective:To explore the protective effect of acupuncture against myocardial injury in rats with stress-induced prehypertension (SIPH) by observing the genetic expression of myocardial endothelin-1 (ET-1) and atrial natriuretic peptide (ANP).Methods:Thirty-six Wistar rats were randomized into three groups:the control group,model group,and model + acupuncture (AP) group (n =12 rats per group).During the 11-day modeling period,the model group and the model + AP group experienced plantar electric stimulation in combination with noise exposure,and daily acupuncture intervention was applied simultaneously in the model + AP group;the control group did not experience modeling or acupuncture.Systolic pressure (SP) was measured the day before modeling began,and on the 3rd,5th,7th,9th,and 11th day after modeling initiation.On the 12th day,histopathological observation of the left ventricle was made with hematoxylin-eosin staining and quantitative genetic expression of myocardial ET-1,and ANP was tested by quantitative real-time polymerase chain reaction (PCR).Results:SP was higher in the model group than the control group on the 3rd,5th,7th,9th,and 11th days (all P <.01).SP in the model + AP group was lower than that in the control group on the 5th and 7th days (respectively,P =.008,P =.002) and on the 9th and 11th days (P =.029,P =.039).Hematoxylin-eosin staining showed normal myocardial cellular structure in the control group.The model group showed disordered arrangement of cardiac cells with morphological changes in some nuclei,including enlargement or dissolution;there was also infiltration of inflammatory cells and proliferation of collagen fibers.In the model + AP group,most of the myocardial cells were normally structured,and only part of the cells had morphological changes with enlarged nuclei or dissolution.Real-time PCR showed that expression of ET-1 and ANP mRNA in the model group was greater than the control group (respectively,P =.024,P =.000101).The model + AP group had lower expression of ET-1 and ANP mRNA compared with the model group (respectively,P =.033,P =.043).Conclusion:Acupuncture may lower blood pressure and downregulate the genetic expression of myocardial ET-1 and ANP in SIPH rats,suggesting a protective effect of acupuncture against myocardial damage.

Sleeve gastrectomy ameliorates endothelial function and prevents lung cancer by normalizing endothelin-1 axis in obese and diabetic rats

BACKGROUND Previous evidence has implied that obesity is an independent risk factor for developing cancer.Being closely related to obesity,type 2 diabetes mellitus provides a suitable environment for the formation and metastasis of tumors through multiple pathways.Although bariatric surgeries are effective in preventing and lowering the risk of various types of cancer,the underlying mechanisms of this effect are not clearly elucidated.AIM To uncover the role and effect of sleeve gastrectomy(SG)in preventing lung cancer in obese and diabetic rats.METHODS SG was performed on obese and diabetic Wistar rats,and the postoperative transcriptional and translational alterations of the endothelin-1(ET-1)axis in the lungs were compared to sham-operated obese and diabetic rats and age-matched healthy controls to assess the improvements in endothelial function and risk of developing lung cancer at the postoperative 4 th,8 th,and 12 th weeks.The risk wasalso evaluated using nuclear phosphorylation of H2 A histone family member X as a marker of DNA damage(double-strand break).RESULTS Compared to obese and diabetic sham-operated rats,SG brought a significant reduction to body weight,food intake,and fasting blood glucose while improving oral glucose tolerance and insulin sensitivity.In addition,ameliorated levels of gene and protein expression in the ET-1 axis as well as reduced DNA damage indicated improved endothelial function and a lower risk of developing lung cancer after the surgery.CONCLUSION Apart from eliminating metabolic disorders,SG improves endothelial function and plays a protective role in preventing lung cancer via normalized ET-1 axis and reduced DNA damage.

Neuropathy optic glaucomatosa induced by systemic hypertension through activation endothelin-1 signaling pathway in central retinal artery in rats

AIM： To evaluate effect of hypertension on retinal ganglion cell（RGC） apoptosis, intraocular pressure（IOP）,and the activation of endothelin-1（ET-1） signaling pathway in central retinal artery（CRA） in rats.METHODS： The experimental study was performed on20 male Sprague Dawley rats that were divided into control group, and hypertension groups. The hypertension was induced by subcutaneous deoxycorticoacetate（DOCA）10 mg/kg twice a week and administered 0.9% Na Cl solution daily for 2, 6, and 10 wk. Blood pressure（BP） was measured using animal BP analyzer. IOP was measured by handheld tonometry. Retinal tissue preparations by paraffin blocks were made after enucleation. The expression of ET-1, e NOS, ET-1 receptor A（ETRA）, ET-1receptor B（ETRB）, and phosphorylated myosin light chain kinase（MLCK）, and caldesmon（Ca D） in CRA and RGC apoptosis were evaluated through immunofluorescent staining method then observed using laser scanning confocal microscopy. RESULTS： BP significantly increased in all of the hypertension groups compared to control（P =0.001）.Peak IOP elevation（7.78±4.14 mm Hg） and RGC apoptosis（576.15±33.28 Au） occurred on 2wk of hypertension. ET-1expression（1238.6±55.1 Au） and e NOS expression（2814.2±70.7 Au） were found highest in 2wk of hypertension,although the ratio of ET-1/e NOS decreased since 2wk.ETRAreached peak expression in 10 wk of hypertension（1219.4 ±6.3 Au）, while ETRBsignificantly increased only in 2 weeks group（1069.2 ±9.6 Au）. The highest MLCK expression（1190.09±58.32 Au）, Ca D（1670.28±18.36 Au）were also found in 2wk of hypertension.CONCLUSION： Hypertension effects to activation of ET-1 signaling pathway significantly in CRA, elevation of IOP, and RGC apoptosis. The highest value was achieved at 2wk, which is the development phase of hypertension.

Dry environment on the expression of lacrimal gland S100A9,Anxa1,and Clu in rats via proteomics

●AIM:To investigate the underlying mechanism of dry environment(autumn dryness)affecting the lacrimal glands in rats.●METHODS:Twenty Sprague-Dawley rats were randomly divided into two groups.The rats were fed in specific pathogen free environment as the control group(n=10),and the rats fed in dry environment as the dryness group(n=10).After 24d,lacrimal glands were collected from the rats.The tissues morphology was observed by hematoxylineosin(HE)staining.Tandem mass tags(TMT)quantitative proteomics analysis technology was used to screen the differential expressed proteins of lacrimal glands between the two groups,then bioinformatics analysis was performed.Further,the immunohistochemical(IHC)method was used to verify the target proteins.●RESULTS:In dryness group,the lacrimal glands lobule atrophied,the glandular cavities enlarged,the sparse nuclear distribution and scattered inflammatory infiltration between the acinus were observed.The proteomics exhibited that a total of 195 up-regulated and 236 downregulated differential expressed proteins screened from the lacrimal glands of rats.It was indicated that the biological processes(BP)of differential expressed proteins mainly included cell processes and single BP.The cellular compositions of differential expressed proteins mainly located in cells,organelles.The molecular functions of differential expressed proteins mainly included binding,catalytic activity.Moreover,the Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis showed that the differential expressed proteins mainly involved lysosome,complement and coagulation cascade,and ribosome pathway.The IHC result verified that the up-regulated expression proteins of Protein S100A9(S100A9),Annexin A1(Anxa1),and Clusterin(Clu)in lacrimal glands of rats in dryness group were higher than control group.●CONCLUSION:The up-regulated expression proteins of S100A9,Anxa1,and Clu may be the potential mechanisms of dry eye symptoms caused by dry environment.This study provides clues of dry environments causing eye-related diseases for further studies.

N-acetylserotonin alleviates retinal ischemia-reperfusion injury via HMGB1/RAGE/NF-κB pathway in rats

AIM:To observe the effects of N-acetylserotonin(NAS)administration on retinal ischemia-reperfusion(RIR)injury in rats and explore the underlying mechanisms involving the high mobility group box 1(HMGB1)/receptor for advanced glycation end-products(RAGE)/nuclear factor-kappa B(NF-κB)signaling pathway.METHODS:A rat model of RIR was developed by increasing the pressure of the anterior chamber of the eye.Eighty male Sprague Dawley were randomly divided into five groups:sham group(n=8),RIR group(n=28),RIR+NAS group(n=28),RIR+FPS-ZM1 group(n=8)and RIR+NAS+FPS-ZM1 group(n=8).The therapeutic effects of NAS were examined by hematoxylin-eosin(H&E)staining,and retinal ganglion cells(RGCs)counting.The expression of interleukin 1 beta(IL-1β),HMGB1,RAGE,and nod-like receptor 3(NLRP3)proteins and the phosphorylation of nuclear factorkappa B(p-NF-κB)were analyzed by immunohistochemistry staining and Western blot analysis.The expression of HMGB1 protein was also detected by enzyme-linked immunosorbent assay(ELISA).RESULTS:H&E staining results showed that NAS significantly reduced retinal edema and increased the number of RGCs in RIR rats.With NAS therapy,the HMGB1 and RAGE expression decreased significantly,and the activation of the NF-κB/NLRP3 pathway was antagonized along with the inhibition of p-NF-κB and NLRP3 protein expression.Additionally,NAS exhibited an anti-inflammatory effect by reducing IL-1βexpression.The inhibitory of RAGE binding to HMGB1 by RAGE inhibitor FPS-ZM1 led to a significant decrease of p-NF-κB and NLRP3 expression,so as to the IL-1βexpression and retinal edema,accompanied by an increase of RGCs in RIR rats.CONCLUSION:NAS may exhibit a neuroprotective effect against RIR via the HMGB1/RAGE/NF-κB signaling pathway,which may be a useful therapeutic target for retinal disease.

Astrocytic endothelin-1 overexpression impairs learning and memory ability in ischemic stroke via altered hippocampal neurogenesis and lipid metabolism

Vascular etiology is the second most prevalent cause of cognitive impairment globally.Endothelin-1,which is produced and secreted by endothelial cells and astrocytes,is implicated in the pathogenesis of stroke.However,the way in which changes in astrocytic endothelin-1 lead to poststroke cognitive deficits following transient middle cerebral artery occlusion is not well understood.Here,using mice in which astrocytic endothelin-1 was overexpressed,we found that the selective overexpression of endothelin-1 by astrocytic cells led to ischemic stroke-related dementia(1 hour of ischemia;7 days,28 days,or 3 months of reperfusion).We also revealed that astrocytic endothelin-1 overexpression contributed to the role of neural stem cell proliferation but impaired neurogenesis in the dentate gyrus of the hippocampus after middle cerebral artery occlusion.Comprehensive proteome profiles and western blot analysis confirmed that levels of glial fibrillary acidic protein and peroxiredoxin 6,which were differentially expressed in the brain,were significantly increased in mice with astrocytic endothelin-1 overexpression in comparison with wild-type mice 28 days after ischemic stroke.Moreover,the levels of the enriched differentially expressed proteins were closely related to lipid metabolism,as indicated by Kyoto Encyclopedia of Genes and Genomes pathway analysis.Liquid chromatography-mass spectrometry nontargeted metabolite profiling of brain tissues showed that astrocytic endothelin-1 overexpression altered lipid metabolism products such as glycerol phosphatidylcholine,sphingomyelin,and phosphatidic acid.Overall,this study demonstrates that astrocytic endothelin-1 overexpression can impair hippocampal neurogenesis and that it is correlated with lipid metabolism in poststroke cognitive dysfunction.

Protective effect of liraglutide on the myocardium of type 2 diabetic rats by inhibiting polyadenosine diphosphate-ribose polymerase-1

BACKGROUND In recent years,studies have found that the occurrence and development of diabetic cardiomyopathy(DCM)is closely related to an increase in polyadenosine diphosphate-ribose polymerase-1(PARP-1)activity.PARP-1 activation could be involved in the pathophysiological process of DCM by promoting oxidative stress,the inflammatory response,apoptosis and myocardial fibrosis.AIM To investigate the mechanism of liraglutide in improving myocardial injury in type 2 diabetic rats,further clarified the protective effect of liraglutide on the heart,and provided a new option for the treatment of DCM.METHODS Forty healthy male SD rats aged 6 wk were randomly divided into two groups,a normal control group(n=10)and a model group(n=30),which were fed an ordinary diet and a high-sugar and high-fat diet,respectively.After successful modeling,the rats in the model group were fed a high-glucose and high-fat diet for 4 wk and randomly divided into a model group and an intervention group(further divided into a high-dose group and a low-dose group).The rats were fed a high-glucose and high-fat diet for 8 wk and then started drug intervention.Blood samples were collected from the abdominal aorta to detect fasting blood glucose and lipid profiles.Intact heart tissue was dissected,and its weight was used to calculate the heart weight index.Haematoxylin and eosin staining was used to observe the pathological changes in the myocardium and the expression of PARP-1 in the heart by immunohistochemistry.RESULTS The body weight and heart weight index of rats in the model group were significantly increased compared with those in the normal control group,and those in the intervention group were decreased compared with those in the model group,with a more obvious decrease observed in the high-dose group(P<0.05).In the model group,myocardial fibers were disordered,and inflammatory cells and interstitial fibrosis were observed.The cardiomyopathy of rats in the intervention group was improved to different degrees,the myocardial fibers were arranged neatly,and the myocardial cells were clearly striated;the improvement was more obvious in the high-dose group.Compared with the normal control group,the expression of PARP-1 in myocardial tissue of the model group was increased,and the difference was statistically significant(P<0.05).After liraglutide intervention,compared with the model group,the expression of PARP-1 in myocardial tissue was decreased,and the reduction was more obvious in the high-dose group(P<0.05)but still higher than that in the normal control group.CONCLUSION Liraglutide may improve myocardial injury in type 2 diabetic rats by inhibiting the expression of myocardial PARP-1 in a dose-dependent manner.

Protective Effect and Mechanism of n-butanol Extract from Diploclisia glaucescens(B1.)Diels on Rats with Adjuvant Arthritis

[Objectives]To study the protective effect and mechanism of n-butanol extract of Diploclisia glaucescens(B1.)Diels on rats with adjuvant arthritis.[Methods]A rat adjuvant arthritis(AA)model with similarities to a clinical RA(rheumatoid arthritis)patient was used,and the model was made by injection of Complete Freund s adjuvant(CFA).Body mass and joint swelling degree were used as indicators,and the organ index was calculated and the synovial tissue of rats was examined under microscope to evaluate the protective effect of n-butanol extract on arthritis.The effects of n-butanol extract on TNF-α,IL-1βand PGE_(2)contents in rat serum were detected by ELISA kit.[Results]Arthritic rats experienced significant weight loss;the n-butanol extract reduced the joint swelling in rats.It exerted an effect on rat organs and reduced the contents of TNF-α,IL-1βand PGE_(2) in rat serum,and also reduced synovial inflammation in rats.[Conclusions]The n-butanol extract of D.glaucescens can protect rats with adjuvant arthritis by reducing the content of inflammatory factors.

Effect of Lycium barbarum Polysaccharides on the expression of endothelin-1 and its receptors in an ocular hypertension model of rat glaucoma

Lycium barbarum, a traditional Chinese anti-aging herb, has been shown to protect retinal ganglion cells （RGCs） in a rat chronic ocular hypertension （COH） model. Here, we investigated the expression of endothelin-1 （ET-1）, a strong vasoconstrictor, and its receptors, ETA and ETB, in the COH model and assessed the effects of Lycium barbarum on the ET-1 axis. Elevated intraocular pressure （IOP） was induced in the right eye of SD rats using argon laser photocoagulation. （1） The expression of ET-1, ETA and ETB in normal and COH retinas was studied. （2） Some COH rats were fed daily with Lycium barbarum Polysaccharides （LBP） using 1 mg/kg or phosphate-buffered saline （PBS） for 3 weeks （started 1 week before photocoagulation）. The effects of LBP on the expression of ET-1 and its receptors, ETA and ETB, in COH retina were evaluated. A semi-quantitative analysis of staining intensity was used to evaluate the expression levels of ET-1, ETA and ETB in retinal vasculature. We found that （1） Under COH condition, the immunoreactivity of ET-1 was increased in retina associated with an increase of ETB receptor immunoreactivity and a decrease of ETA receptor immunoreactivity. （2） After feeding COH rats with LBP, the expression of ET-1 was decreased with an increase of ETA expression and a decrease of ETB expression in the retina, especially in RGCs. （3） By comparing the staining intensity in the vasculature of COH retina in LBP-fed group with PBS-fed group, there was a decrease in the expression of ET-1 and ETA and an increase in ETB. In summary, ET-1 expression was up-regulated in the retina in COH model. LBP could decrease the expression of ET-1 and modulate the expression of its receptors, ETA and ETB, under the condition of COH. The neuroprotective effect of LBP on RGCs might be related to its ability to regulate the ET-1-mediated biological effects on RGCs and retinal vasculature.

Effect of Salvia Miltiorrhiza Injection on Blood Pressure and Cardiac Function in Rats with Gestational Hypertension and Preeclampsia

Objective: This study is to observe the effects of Salvia miltiorrhiza injection on blood pressure and cardiac function in rats with pregnancy-induced hypertension and preeclampsia. Methodology: Syncytiotrophoblast microvilli (stbm) and l-arginine nitrosyl methyl ester were screened out via caudal vein injection. Twenty gestational hypertension-preeclampsia model SD (Sprague Dawley) rats successfully induced by L-NAME (L-arginine Nitrosyl methyl ester) were randomly divided into 2 groups (model group and Danshen injection group, n = 10). Then another 10 normal pregnant SD rats without model were selected as blank control group. The Salvia miltiorrhiza injection group was given Salvia miltiorrhiza injection (0.5 g?kg?1?d?1) through tail vein, and the control group and model group were given equal volume of normal saline through tail vein injection. All three groups were treated by tail vein injection once a day (d) for 7 days. After treatment, heart rate (HR), Systolic pressure (SP), diastolic pressure (DP) and mean arterial pressure (MAP) were measured by tail artery. Left ventricular end-diastolic diameter (LVDd) and Left ventricular end systolic diameter (LVDs) were recorded by echocardiography. Left ventricular end diastolic pressure (LVEDP), left ventricular systolic pressure (LVSP), left ventricular ejection fraction (left ventricular ejection) fraction, LVEF) and the maximum rate of increase/decrease of left ventricular pressure during isovolemic systole (+dp/dtmax/?dp/dtmax);Endothelin-1 (ET-1) levels in rat tail vein blood were detected by ELISA. Results: SP, DP, MP, HR, LVSP, LVDs and ?dp/dtmaxx were all decreased, plasma ET-1 expression was low, and LVDd, LVEDP, LVEF, and +dp/dtmax were all increased in the Salvia miltiorroot injection group, with statistical significance compared to the model group (p Conclusion: Salvia miltiorrhiza injection can improve the cardiac function and reduce blood pressure in rats with pregnancy-induced hypertension and preeclampsia, and the mechanism may be related to alleviating systemic arteriolar spasm by regulating ET-1 level.

Protective Effects of Ginsenoside Rb1 on Septic Rats and Its Mechanism

This study aims to observe the protective effects of ginsenoside Rbl on liver and lung in rats with septic shock and reveal its mechanism. Rats were randomly divided into three groups： sham, cecal ligation and puncture （CLP）, and CLP with ginsenoside Rb1. Then, the survival rate, arterial blood pressure, TLR4 mRNA, and TNF-α levels were determined. The liver and lung tissues were stained with hematoxylin-eosin （HE）. The overall survival rate of the Rb1 group was significantly higher than that of the CLP group. Mean arterial blood pressure went down in both the CLP and Rb1 groups after CLP, and there was a significant difference both in the sham and Rb1 groups when compared with the CLP group. The Rb1 treatment group had markedly lower TLR4 mRNA expression and TNF-a levels than the CLP group. In the CLP group, pathology showed swelling, degeneration, necrosis, and neutrophii infiltration in the liver and alveolar epithelial cells. However, in the Rb1 group, there was mild degeneration and slight neutrophil infiltration, but no obvious necrosis. Rb1 may improve the survival rate, ameliorate arterial blood pressure, and protect the liver and lung in septic shock rats by downregulating the expression of TLR4 mRNA and inhibiting the production of TNF-α.

Effect of Heme Oxygenase-1 Inducer Hemin on Chronic Renal Failure Rats

Summary: The role of HO-1 inducer, hemin, in chronic renal failure (CRF) rats and its possible mechanism of action was studied. 5/6 subtotal nephrectomy was performed to establish chronic renal failure model. Rats were randomly assigned to 4 groups: sham-operated group, CRF group, ferrous gluconate group and hemin group. At the 10th week after operation, serum creatinine, BUN, RBC, HGB and HCT were measured. Renal pathologic changes were observed. RT-PCR and immunohistochemistry were used to detect the expression and distribution of HO-1. RT-PCR and radioimmunoassay was used to determine the expression of ET-1 in the kidney and plasma. The results showed that as compared with CRF group, serum creatinine and BUN in hemin group were reduced significantly and nephrogenic anemia was improved markedly. Glomerular mesangial proliferation and interstitial lesion were also ameliorated significantly. Hemin not only increased the expression of HO-1 but also reduced the expression of ET-1 in the kidney. The level of ET-1 protein in the plasma was also reduced after hemin treatment. Most of these indexes were not obviously changed in ferrous gluconate group. It was suggested that through inducing the expression of HO-1 and reducing the level of ET-1 in the kidney and plasma, hemin plays an important protective role in 5/6 subtotal nephrectomized rats.

Effect of Hypertonic Versus Isotonic Saline Resuscitation on Heme Oxygenase-1 Expression in Visceral Organs Following Hemorrhagic Shock in Rats

To compare the early effects of hypertonic and isotonic saline resuscitation on heme oxygenase-1 （HO-1） expression in organs of rats with hemorrhagic shock. Rats were randomly divided into hypertonic saline resuscitation （HTS）, normal saline resuscitation （NS） and sham groups. HO-1 mRNA, protein expression and apoptosis were evaluated in organs. In the HTS group, significant difference was noted in HO-1 protein in small intestinal mucosa and liver compared with the NS and sham groups, and in HO-1 mRNA in liver and kidney compared with the sham group. The apoptosis of small intestinal mucosa, liver, heart, and lung was significantly lower in the HTS group than that in the NS group. In this study, small volume resuscitation with HTS can efficiently up-regulate the expression level of HO-1 in small intestinal mucosa and liver, which may be one of the mechanisms alleviating organ damage.

Effect of 1, 25-Dihydroxyvitamin D_3 on Gastric Carcinogenesis Induced by N-Methyl-N'-nitro-N-nitrosoguanidine in Rats

The effect of 1, 25-dihydroxyvitamin D3 (1, 25 (OH)2D3) given in the post-initiation stage of gastric carcinogenesis induced by N-methyl-N-nitro-N-nitrosoguanidine (MNNG) was investigated in male Wistar rats. Gastric carcinogenesis in rats was induced by administration of MNNG (150 mg·L-1) in drinking water. Four weeks after MNNG exposure, the rats were switched to the diet containing 1, 25 (OH)2D3 (2. 5 μg·kg-1 and 5. 0 μg·kg-1) and maintained on the diet. Animals were killed at week 16 and week 32 for immunohistochemical and histopathological studies. At week 16, the proliferating cell nuclear antingen (PCNA) labeling index in epithelium from the glandular stomach of rats that received 1, 25 (OH)2D3 (5.0 μg·kg-1) in combination with MNNG (150 mg·L-1) were significantly higher when compared with the rats receiving MNNG alone. Supplementation of 1, 25 (OH)2D3 (5. 0 μg·kg-1) in the rats' diet caused a dramatic increase in carcinoma incidence, and the number of individual cancer foci in the glandular stomach of rats receiving MNNG at week 32. It was concluded that certain dose of 1, 25 (OH)2D3 enhanced gastric carcinogenesis induced by MNNG in rats.

Influence of Methionine Supplementation in Chelation of Lead in Rats1

The influence of methionine supplementation on the efficacy of common antidotes to lead poisoning, calcium disodium ethylenediaminetetraacetate (CaNa_2EDTA) and D-penicillamine (DPA), was investigated in rats. The animals were given lead acetate (0.1% in drinking water) for 12 weeks and thereafter treated with CaNa_2EDTA, DPA (0.3mmol/kg, intraperitoneally), DL-methionine (1.34 mmol/kg, intragastrically), or the combination of a chelating agent and methionine for 3 days. While chelating agents enhanced the urinary excretion of Pb, methionine increased the fecal excretion of Pb significantly. Treatment with the combination of a chelating agent and methionine did not potentiate the effect of each antidote. However, methionine supplementation increased the efficacy of both chelating agents in reducing the hepatic and renal Pb burden but not the blood Pb level. The Pb-induced inhibition of blood δ-aminolevulinic acid dehydratase activity and the increase in urinary excretion of δ-aminolevulinic acid were reversed to a certain extent by CaNa_2EDTA, DPA, and methionine but the combination did not improve their individual performances. The beneficial effects of methionine may be attributed to its ability to increase the bioavailability of glutathione (GSH), useful in chelating Pb and counteracting the toxic effects, as evidenced by restoration of the Pb-induced decrease in hepatic GSH level by treatment with methionine. Methionine may be useful as a supportive therapy in chelation of Pb. (c)1989 Academic Press. Inc.

Expression of hypoxia inducible factor-1 alpha and ischemic erythropoietin tolerance in the brain of cerebral ischemic tolerance model rats

BACKGROUND： Hypoxia inducible factor-1 alpha （HIF-1 （x） and erythropoietin（EPO）, possessing neuroprotective effect in the cerebral ischemia, might play an important role in the formation of cerebral ischemic tolerance （IT）. OBJECTIVE：To observe the neuroprotective effect of cerebral ischemic preconditioning（IPC） of rats, and the expression and mechanism of HIF-1α and target gene erythropoietin in the brain tissue following the formation of cerebral IT. DESIGN ： A randomized and controlled observation SETTING： Department of Neurology, the Affiliated Hospital of Medical College, Qingdao University MATERIALS： Totally 84 enrolled adult healthy male Wistar rats of clean grade, weighing 250 to 300 g, were provided by the Animal Experimental Department, Tongji Medical College of Huazhong University of Science and Technology. Ready-to-use SABC reagent kit and rabbit anti-rat HIF-1α monoclonal antibody were purchased from Boshide Bioengineering Co.Ltd （Wuhan）; Rabbit anti-rat EPO monoclonal antibody was purchased from Santa Cruz Company （USA）. METHODS： This experiment was carried out in the Department of Anatomy, Medical College, Qingdao University during March 2005 to March 2006. ① The 84 rats were divided into 3 groups by a lot： IPC group （n=40）, sham-operation group （n=40） and control group （n=4）. In the IPC group, middle cerebral artery was occluded for 2 hours respectively on the 1^st, 3^rd, 7^th, 14^th and 21^st days of the reperfusion following 10-minute preischemia was made using a modified middle cerebral artery second suture method from Zea-Longa. The rats were sacrificed 22 hours after reperfusion in the end of middle cerebral artery occlusion （MCAO）. That was to say, after 10-minute preischemia, suture was exited to the extemal carotid artery and embedded subcutaneously. Middle cerebral artery was occluded again to form the second reperfusion at the set time point after reperfusion. Twenty-two hours later, rats were sacrificed; In the sham-operation group,the preischemia was substituted by sham-operation（only common carotid artery and crotch were exposed, and MCAO by suture was omitted）, and the other procedures were the same as those in the IPC group. In the control group, rats were given sham-operation twice at an interval of one day, and they were sacrificed 24 hours after the second sham-operation. ② Brain tissue was taken from the rats in each group. Cerebral infarction area of each layer was measured with TTC staining, and total cerebral infarction volume （The total cerebral infarction area of each layerxinterspace ） was calculated. After brain tissue was stained by haematoxylin-esoin （HE）, the form of nerve cells was observed under an optical microscope, and the expressions of HIF-1α（and EPO protein in the brain tissue were detected with immunohistochemical method. MAIN OUTCOME MEASURES： ①Cerebral infarction volume;②form of nerve cell; ③ the expression of HIF-1α and EPO protein in the brain tissue. RESULTS：Totally 84 rats were enrolled in the experiment. The dead rats were randomly supplied during the experiment, and finally 84 rats entered the stage of result analysis. ① Detection of cerebral infarction volume of rats in each group： Cerebral infarction volume in the IPC group was significantly smaller than that in the sham-operation group on the 1^st, 3^rd and 7^th days after reperfusion respectively [（161.2±6.9） mm^3 vs （219.9±11.2） mm^3, （134.9±9.0） mm^3 vs （218.6±13.0） mm^3, （142.9±13.7） mm^3 vs （221.3±14.2） mm^3, t=-8.924, 10.587,7.947, P〈 0.01]. ② Observation of nerve cell form of brain tissue： HE staining showed that the ischemic degree, range and cerebral edema degree of IPC group were significantly milder than those of sham-operation group. ③ The expressions of HIF-1α and EPO protein in cerebral cortex and hippocampus ： The expression of HIF-1αof IPC group was significantly higher than that of sham-operation group on the 1^st, 3^rd and 7^th days after reperfusion respectively （125.93±3.79 vs 117.65±5.60, 140.63±4.64 vs 119.33±4.26, 131.15±2.74 vs 107.60±3.89, t=2.449, 6.763,9.899,P 〈 0.05-0.01）. The expression of EPO of IPC group was significantly higher than that of sham-operation group on the 3^rd and 7^th days after perfusion respectively （141.68±3.29 vs 126.33±4.51, 138.88±2.59 vs 125.58±6.18,t=5.499,3.970, P〈 0.05）. CONCLUSION ： ①IPC can protect the never cells in rat brain and the best time to onset of cerebral IT induced by IPC is 1 to 7 days after reperfusion. ② Neuroprotective effect of cerebral IT might be related to the expression of HIF-1α and its target gene EPO.

Disposition and Metabolism of 1 -Nitropropane in Rats and Chimpanzees

The metabolic fate of 1 -nitropropane (1-NP) has not been previously reported. In this study male rats and chimpanzees were given single doses of 40 mg/kg ip and 5 mg/kg iv 1-[1-^(14)C]NP, respectively. The quantitative extent of urinary and fecal elimination was similar in both species. The rats excreted 16.5% ofthedosein urine and 1.7% in feces. For chimpanzees the respective values were 14.8 and 1.2%. Experiments with rats demonstrated that the major route of elimination was by exhalation. With a total elimination via the lungs of 72.6%, rats expired 10.3% of the dose as unchanged 1-NP. Five polar metabolites were isolated from the urine of chimpanzees. The two major metabolites were identified as 3-hydroxypropionic acid and 7V-methyl-N-2-(methylsulfinyl)ethylpropionic acid amide (NMPA). Both substances were also excreted in rat urine. The two identified metabolites indicate that 1-NP was degraded to propionic acid, part of which was modified to 3-hydroxypropionic acid or NMPA. A hypothetical pathway for the biochemical generation of NMPA is suggested.(c)1989 Academic Press, Inc.

The effect of Wujiadan Recipe on serum sex hormone and expression of Kiss-1, GPR54 and GnRH in arcuate nucleus of hypothalamus in ovariectomized rats

Objective:To explore the effect of wujiadan Recipe on the expression of FSH,E2 in serum and KiSS-1,GPR54,GnRH mRNA in hypothalamic arcuate nucleus tissue homogenate of ovariectomized rats,and to further explore the mechanism of wujiadan Recipe on menopausal syndrome.Methods:Sixty-four adult female rats were randomly divided into three groups:blank group,model group,Chinese medicine control group,western medicine control group,and wujiadan high,medium and low dose groups.Except for the blank group,all the other groups were ovariectomized.The rats in the normal group and the model group were given the same dose of saline once a day.One rat in the blank group died during the experiment.After 4 weeks of continuous administration,blood was collected from abdominal aorta and brain stereotaxic localization was performed to preserve the arcuate nucleus of hypothalamus.The levels of FSH and E2 in serum were detected by enzyme-linked immunosorbent assay(ELISA),and the expression of Kiss-1,GPR54 and GnRH mRNA in arcuate nucleus of hypothalamus were detected by PCR.Results:1.Compared with the blank group,FSH level in the model group was significantly higher(P<0.01),and E2 level was significantly lower(P<0.01).Compared with the model group,the level of serum E2 in the western medicine control group increased significantly(P.The serum FSH content in each group decreased,especially in the high dose group and the western medicine control group(P<0.01),and in the Chinese medicine control group,the middle dose group and the low dose group(P<0.05).Compared with the blank group,the expression of KiSS-1 mRNA,GPR54 mRNA and GnRH mRNA in the model group increased significantly(P<0.01);compared with the model group,the expression of KiSS-1 mRNA and GPR54 mRNA in the high dose group,middle dose group and Western medicine control group of wujiadan prescription decreased significantly(P<0.05).Compared with the model group,the expression of GnRH mRNA in the high dose group and the western medicine control group decreased significantly(P<0.01);the middle dose group of wujiadan decreased significantly(P<0.05).Conclusion:Wujiadan recipe can improve the serum sex hormone level of castrated rats,and reduce the over expression of KiSS-1,GPR54 and GnRH mRNA in hypothalamic arcuate nucleus of castrated rats,which may be the reproductive endocrine mechanism of wujiadan recipe in the treatment of menopausal syndrome.