The Experimental Study on the Effect Calcitonin Gene related Peptide on Bone Resorption Mediated by Interleukin-1

To investigate the effect of calcitonin gene related peptide (CGRP) on bone resorption mediated by interleukin 1β(IL 1β) in vitro , the osteoclasts isolated from the long bones of newborn SD rats were co cultured with osteoblasts on ivory slices placed in 24 well plates . 24 h later, conditioned media containing CGRP and/or IL 1β were added to the wells respectively, and continued culturing for 48 h. After the cells were stripped off by ultrasonication, the ivory slices were stained in toludine blue. The number and the total area of resorption lacunae on each slice were measured by computer imaging analysis system. Our results showed that IL 1β significantly stimulated bone resorption, but CGRP inhibited the effect mediated by IL 1β in a dose dependent manner. It is suggested that CGRP may inhibit osteoclastic bone resorption through two ways: One is that CGRP functions directly on osteoclasts to block their activation; the other is that CGRP regulates the release of cytokines by osteoblasts and indirectly affects the function of osteoclasts.

Electroacupuncture at Fengchi(GB20) inhibits calcitonin gene-related peptide expression in the trigeminovascular system of a rat model of migraine

Most migraine patients suffer from cutaneous allodynia; however, the underlying mechanisms are unclear. Calcitonin gene-related peptide（CGRP） plays an important role in the pathophysiology of migraine, and it is therefore, a potential therapeutic target for treating the pain. In the present study, a rat model of conscious migraine, induced by repeated electrical stimulation of the superior sagittal sinus, was established and treated with electroacupuncture at Fengchi（GB20）（depth of 2–3 mm, frequency of 2/15 Hz, intensity of 0.5–1.0 m A, 15 minutes/day, for 7 consecutive days）. Electroacupuncture at GB20 significantly alleviated the decrease in hind paw and facial withdrawal thresholds and significantly lessened the increase in the levels of CGRP in the trigeminal ganglion, trigeminal nucleus caudalis and ventroposterior medial thalamic nucleus in rats with migraine. No CGRP-positive cells were detected in the trigeminal nucleus caudalis or ventroposterior medial thalamic nucleus by immunofluorescence. Our findings suggest that electroacupuncture treatment ameliorates migraine pain and associated cutaneous allodynia by modulating the trigeminovascular system ascending pathway, at least in part by inhibiting CGRP expression in the trigeminal ganglion.

Effect of warm acupuncture on nitric oxide synthase and calcitonin gene-related peptide in a rat model of lumbar nerve root compression

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.

Preliminary study on androgen dependence of calcitonin gene-related peptide in rat penis

Aim: To study the androgen dependence of the neurotransmitter, calcitonin gene-related peptide (CGRP) in rat penis. Methods: Forty-four Sprague-Dawley rats were randomly divided into Group A (intact controls), Group B (castrated) and Group C (gavaged with finasteride 4.5 mg·kg^(-1).day^(-1)). Four and ten weeks later respectively, half of rats in each group were anaesthetized. Blood samples were taken for the measurement of serum testosterone and dihydrotestosterone (DHT) by means of radioimmunoassay. Penile samples were harvested for the investigation of calcitonin gene related peptide (CGRP)-immunoreactive nerve fibers with immunohistochemistry. The computer-assisted imaging analysis system was applied to calculate the area proportion of the CGRP-positive nerve fibers (CGRP-PNF) in each group. Results: 1) Both 4 and 10 weeks later, testosterone and DHT levels in Group B decreased significantly compared with those in Group A, (P < 0.05, P < 0.01, respectively); DHT level in Group C was also significantly decreased in comparison with that in Group A for both 4- and 10- week animals (P < 0.05); 2) There was no significant differences in area proportion of CGRP-PNF among Groups A, B and C 4 weeks after treatments (P > 0.05); However, 10 weeks later, the proportion of CGRP-PNF in Groups B and C was significantly less than that in Group A (P < 0.01);3) The proportion of CGRP-PNF of 4-week animals in Groups B and C was significantly higher than that of 10-week animals (P < 0.05). Conclusion: The expression of neurotransmitter, CGRP may depend on androgens, including testosterone and DHT in rat penis.

Relationship of calcitonin gene-related peptide with disease progression and prognosis of patients with severe traumatic brain injury

Calcitonin gene-related peptide（CGRP） has been implicated in multiple functions across many bioprocesses; however, whether CGRP is associated with severe traumatic brain injury（TBI） remains poorly understood. In this study, 96 adult patients with TBI（enrolled from September 2015 to December 2016） were divided into a mild/moderate TBI group（36 males and 25 females, aged 38 ± 13 years） and severe TBI group（22 males and 13 females, aged 38 ± 11 years） according to Glasgow Coma Scale scores. In addition, 25 healthy individuals were selected as controls（15 males and 10 females, aged 39 ± 13 years）. Radioimmunoassay was used to detect serum levels of CGRP and endothelin-1 at admission and at 12, 24, 48, 72 hours, and 7 days after admission. CGRP levels were remarkably lower, but endothelin-1 levels were obviously higher in the severe TBI group compared with mild/moderate TBI and control groups. Levels of CGRP were remarkably lower, but endothelin-1 levels were obviously higher in deceased patients compared with patients who survived. Survival analysis and logistic regression showed that both CGRP and endothelin-1 levels were associated with patient mortality, with each serving as an independent risk factor for 6-month mortality of severe TBI patients. Moreover, TBI patients with lower serum CGRP levels had a higher risk of death. Thus, our retrospective analysis demonstrates the potential utility of CGRP as a new biomarker, monitoring method, and therapeutic target for TBI.

Substance P and calcitonin gene-related peptide expression in dorsal root ganglia in sciatic nerve injury rats

The neuropeptides, substance P and calcitonin gene-related peptide, have been shown to be involved in pain transmission and repair of sciatic nerve injury. A model of sciatic nerve defect was prepared by dissecting the sciatic nerve at the middle, left femur in female Sprague Dawley rats. The two ends of the nerve were encased in a silica gel tube. L5 dorsal root ganglia were harvested 7, 14 and 28 days post sciatic nerve injury for immunohistochemical staining. Results showed that substance P and cal- citonin gene-related peptide expression increased significantly in dorsal root ganglion of rats with sci- atic nerve injury. This increase peaked at 7 days, declined at 14 days, and reduced to normal levels by 28 days post injury. The findings indicate that the neuropeptides, substance P and calcitonin gene- related peptide, mainly increased in the early stages after sciatic nerve injury.

Transient receptor potential channel A1 involved in calcitonin gene-related peptide release in neurons

Transient receptor potential channel A1 is one of the important transducers of noxious stimuli in the primary afferents, which may contribute to generation of neurogenic inflammation and hyperalgesia. The present study was designed to investigate if activation of transient receptor potential channel A1 may induce calcitonin gene-related peptide release from the primary afferent neurons. We found that application of allyl isothiocyanate, a transient receptor potential channel A1 activator, caused calcitonin gene-related peptide release from the cultured rat dorsal root ganglion neurons. Knock- down of transient receptor potential channel A1 with an antisense oligodeoxynucleotide prevented calcitonin gene-related peptide release by allyl isothiocyanate application in cultured dorsal root ganglion neurons. Thus, we concluded that transient receptor potential channel A1 activation caused calcitonin gene-related peptide release in sensory neurons.

Relationship among plasma endothelin, calcitonin gene-related peptide and blood flow rate of bilateral vertebral arteries in patients with cervical vertigo

Objective： To investigate the relationship among plasma endothelin（ET）, calcitonin gene-related peptide（CGRP） and blood flow rate of bilateral vertebral arteries in patients with cervical vertigo（CV） and to assess the effect of ET and CGRP on the onset of CV. Methods：The concentration of ET and CGRP in 64 patients with CV and 30 controls was determined by radioimmunity method. The average blood flow velocity （Vm） of bilateral vertebral arteries was detected by Transcranial Doppler（TCD）. Results：Plasma concen- tration ofET（91.48 ± 9.08 pg/ml） and ET/CGRP ratio value（2.88 ± 0.52） in vertebrobasilar arteriospasm group were both higher than those in vertebrobasilar non-arteriospasm group and in controls, while CGRP concentration（30.66 ± 6.05 pg/ml） in vertebrobasilar arteriospasm group was lower than that in vertebrobasilar non-arteriospasm group and controls respectively. The Vm of bilateral verte- bral arteries in vertebrobasilar arteriospasm group（67.97 ± 11.64 cm/s ） was higher than that in vertebrobasilar non-arteriospasm group and controls respectively, having a positive correlation with ET concentration and ET/CGRP ratio value（r1=0.52, P 〈 0.05; r2=0.59, P 〈 0.05）, but a negative correlation with CGRP concentration（r3=-0.54, P 〈 0.05）. There was no significant difference in ET and CGRP concentration, ET/CGRP ratio value and the Vm of bilateral vertebral arteries between vertebrobasilar non-arteriospasm group and the control group. Conclusion： All the results indicate that ET and CGRP are possibly the most important substance factors at the onset of CV with vertebrobasilar arteriospasm, and their imbalance of regulating vertebrobasilar arterial contraction and relaxation may play an important role in the onset of CV with vertebrobasilar arteriospasm.

Correlation of calcitonin gene-related peptide and endothelin receptor A with subarachnoid hemorrhage

Numerous studies have demonstrated that endothelin-1 combines with endothelin receptor A, resulting in intense vasoconstriction. Although calcitonin gene-related peptide （CGRP） suppresses endothelin-1, CGRP and endothelin receptor A exhibit direct biological effects on brain tissue. The present study analyzed CGRP and endothelin receptor A expression following subarachnoid hemorrhage in rabbits using immunohistochemistry. CGRP expression was significant at 5 days after model establishment, and endothelin receptor A expression was significant at 3 days after model induction. The perimeter of the basilar artery was measured to determine the amount of cerebral vasospasm. Analytical results revealed a significantly shortened basilar artery perimeter following subarachnoid hemorrhage. Changes in the basilar artery perimeter were negatively associated with endothelin receptor A expression, but positively correlated with CGRP expression in vessels. These results suggest that following subarachnoid hemorrhage, CGRP and endothelin receptor A expressions dynamically changed in brain vessels and tissues, although these changes were not synchronous. Changes in endothelin receptor A expression exhibited a significant effect on the occurrence and development of delayed cerebral vasospasm and delayed neuronal death, while CGRP relaxed vessels and protected nerves.

Calcitonin gene-related peptide in anterior and posterior horns of spinal cord after brachial plexus injury

BACKGROUND： The changes of calcitonin gene-related peptide （CGRP） expression are closely associated with peripheral nerve injury, whereas it should be further investigated whether the damage of central nerve can lead to the changes of CGRP expression, and whether it is associated with the neural regeneration and repair. OBJECTIVE： To observe the changing law of CGRP expression in the anterior and posterior horns of spinal cord following brachial plexus injury. DESIGN： A randomized controlled trial. SETTINGS： Department of Anatomy, Yunyang Medical College; Department of Anatomy, Basic Medical College, Sun Yat-sen University. MATERIALS： Sixty-five adult male SD rats of clean degree, weighing 180 - 220 g, provided by the experimental animal center of the Basic Medical College, Sun Yat-sen University, were randomly divided into control group （n =5） and experimental group （n =60）, and the latter was subdivided into three damage groups： avulsion of anterior root group （n =20）, disjunction of posterior root group （n =20） and transection of spinal cord group （n =20）. Diaminobenzidine （DAB） chromogen, rabbit anti-CGRP polyclonal antibody were the products of Sigma Company; Leica image analytical apparatus was produced by QUIN Company （Germany）; Histotome by Sigma Company. METHODS： The experiments were carried out in the Department of Anatomy, Basic Medical College, Sun Yat-sen University from September 2004 to March 2005. Three kinds of models of brachial plexus injury were established： In the avulsion of anterior root group, right C7 anterior root was avulsed, and the distal nerve residual root was transected. In the disjunction of posterior root group, right C7 anterior root was avulsed and right C5 - T1 posterior horns were cut to block the sensory afferent pathway. In the transection of spinal cord group, right C7 anterior root was avulsed and C5-6 segments of right spinal cord were semi-transected to block the cortical descending pathway. In the control group, C5 - T1 vertebral plates were prayed open, and then the skin was sutured. The C7 segments of spinal cord were removed on the 1^st, 3^rd, 7^th and 14^th days postoperatively respectively, and the CGRP expressions in the anterior and posterior horns of spinal cord were determined and analyzed using immunohistochemical method and image analysis. MAIN OUTCOME MEASURES： ① Number of CGRP immuno-positive motor neurons in the anterior horn of spinal cord; ② Total area ofCGRP immuno-positive fibers in the posterior horn of spinal cord. RESULTS： All the 65 rats were involved in the analysis of results. ① Number of CGRP immuno-positive motor neurons in the anterior horn of spinal cord： CGRP immuno-positive motor neurons could be observed in the anterior horns of C7 spinal cord in the control group and damage groups, the neurons had big cell body with stained cytoplasm, appeared as brown granules, and mainly distributed in the ventral lateral anterior horn of spinal cord. On the Ist day postoperatively, the number of CGRP positive neurons was obviously higher in the in the avulsion of anterior root group than in the control group （P 〈 0.01）, whereas obviously lower in the disjunction of posterior root group than in the control group （P 〈 0.01）, and there was no obvious difference between the transection of spinal cord group and the control group （P 〉 0.05）. On the 7^th day, the numbers of CGRP positive neurons in the damage groups were obviously higher than that in the control group （P 〈 0.01）, also obviously different from those on the 1^st day in the same group respectively （P 〈 0.01）. On the 14^th day, the number of CGRP positive neurons in the disjunction of posterior root group was decreased, but there was no obvious difference as compared with that in the control group, whereas those in the avulsion of anterior root group and transection of spinal cord group were still obviously higher than that in the control group （P 〈 0.01）. The number of CGRP positive neurons was the most in the avulsion of anterior root group, followed by the transection of spinal cord group, and the least in the disjunction of posterior root group, and there were significant differences among them （P 〈 0.01）. ② Total area of CGRP immuno-positive fibers in the posterior horn of spinal cord： Dense CGRP immuno-positive nerve fibers distributed in the layers Ⅰ and Ⅱ of the C7 posterior horn of spinal cord in the control group. On the 1^st day postoperatively, the total areas of CGRP positive fibers in the avulsion of anterior root group and transection of spinal cord group were obviously larger than that in the control group （P 〈 0.01）, whereas there was no obvious difference between the disjunction of posterior root group and control group. On the 7^th day, the CGRP expression in the posterior horn of spinal cord decreased to the lowest level in the disjunction of posterior root group, whereas there were no obvious differences in the avulsion of anterior root group and transection of spinal cord group as compared with that in the control group （P 〉 0.05）. On the 14^th day, the area continued to decrease in the avulsion of anterior root group and transection of spinal cord group, and it was obviously lower in the transection of spinal cord group than in the control group （P 〈 0.01）, and it was slightly increased in the disjunction of posterior root group as compared with that on 7^th day, but still obviously lower than that in the control group （P 〈 0.01）. CONCLUSION： The expression and role of CGRP are in discrepancy in the anterior and posterior horns of spinal cord after brachial plexus injury. The CGRP in anterior horn of spinal cord are derived from the cell body of motor neurons, and may be involved in the repairing mechanism of nerve injury regeneration; Whereas those in the posterior horn are mainly derived from posterior root ganglion, and may be associated with the conduction of noxious stimulations.

EXPRESSION OF CALCITONIN GENE-RELATED PEPTIDE IN FACIAL NERVE OF HEMIFACIAL SPASM

Objective To study the immunoreactivity of Calcitonin gene-related peptide (CGRP) in the facial nerve when Hemifacial Spasm is occurring. Methods The electrophysiological technique was used to explore abnormal muscle response (AMR) which was characteristic of Hemifacial Spasm.The animal models of Hemifacial Spasm in New Zealand white rabbits were established by compressing the main trunk of artificial demyelinated facial nerve with the temporal superficial artery. At 6 weeks after surgery, the facial nerves were taken from the experimental group and control one, the immunohistochemistry for CGRP using polyclonal antibody with ABC kit was performed in the facial nerves; at the same time, the observation for the facial nerves of light and transmission electron microscope was performed. Results The facial nerve demyelinated and the axons retrogressively changed, CGRP immunoreactive positive fibers were significantly detected in experimental groups; whereas this phenomenon was not found in control group. Conclusion CGRP can nutrien the injured facial nerve and plays an important role in the pathogenesis of Hemifacial Spasm.

Changes in plasma calcitonin gene-related peptide and serum neuron specific enolase in rats with acute cerebral ischemia after low-frequency electrical stimulation with different waveforms and intensities

Following acute cerebral ischemia in rats, plasma calcitonin gene-related peptide decreased and the level of serum neuron specific enolase and the volume of the infarction increased. Square-wave and triangular-wave electrical stimulation with low or high intensities could increase the plasma calcitonin gene-related peptide, decrease the serum neuron specific enolase and reduce the infarction volume in the brain in rats with cerebral ischemia. There was no significant difference between different wave forms and intensities. The experimental findings indicate that low-frequency electrical stimulation with varying waveforms and intensities can treat acute cerebral ischemia in rats.

RELATIONSHIP BETWEEN THE PATTERN OF METHYLATION OF CALCITONIN GENE AND ACTIVITY OF METHYLTRANSFERASEIN 8 TUMOR CELL LINES

Objective: The current study was designed to investigate the relationship between the pattern of methylation of calcitonin (CT) gene and the activity of DNA methyltranferase (MTase). Methods: The methylation rate of the 5′ region of the CT gene (CTMR) and the activity of MTase in 6 solid tumor cell lines and 2 leukemia cell lines were determined. CTMR was detected by polymerase chain reaction (PCR) with inter and external references in combination with restriction endonuclease and laser scan technique. MTase activity was examined by isotope labeled microassay. Results: Both CTMR and MTase activity in all tumor cell lines were significantly higher than that of control cells. The increased MTase activity was relative to elevated CTMR. Conclusion: There is prevalence of hypermethylation of CT gene and elevated activity of MTase in malignant cells. The increased MTase activity is one of the possible reasons for CT gene hypermethylation in tumor cells.

Controlling N-methyl-D-aspartate receptor subunit 1 with calcitonin gene related peptide after cerebral ischemic injury

BACKGROUND: Activation of N-methyl-D-aspartate receptor (NMDAR) is a key link of exitotoxicity at the phase of cerebral ischemic injury. Because NMDAR is a main way to mediate internal flow of Ca2+ among glutamic acid receptors, over-excitation can cause neuronal apoptosis. Calcitonin gene related peptide has a strongly biological activity. On one hand, it can protect ischemic neurons through inhibiting the expression of NMDAR1 mRNA; on the other hand, it can play the protective effect through down-regulating the expression of NMDAR1 mRNA by exogenous calcitonin gene related peptide. OBJECTIVE: To observe the expression of NMDAR1 and the regulatory effect of calcitonin gene related peptide on the expression of NMDAR1 mRNA and protein in the cerebral cortex of rats with focal cerebral ischemia/reperfusion (I/R). DESIGN: Randomized controlled animal study. SETTING: China Medical University. MATERIALS: A total of 216 healthy male Wistar rats, general grade, weighing 250-280 g, were selected in this study. Twelve rats were randomly selected to regard as control group; meanwhile, other 204 rats were used to establish middle cerebral artery occlusion/reperfusion (MACO) models. The main reagents were detailed as follows: calcitonin gene related peptide (Sigma Company); calcitonin gene related peptide kit (Boster Company); antibody Ⅰ, Ⅱ and antibody β-actin Ⅰ, Ⅱ of NMDAR1 mRNA and chemiluminescence reagent (Santa Cruz Company, USA). METHODS: The experiment was carried out in the Laboratory of Neurobiology of China Medical University from August 2005 to June 2006. ① Right MCAO models of rats were established to cause focal ischemia and scored based on Zea Longa five-grade scale. If the scores were 1, 2 and 3 after wakefulness, the MACO models were established successfully and involved in the experiment. A total of 120 rats with successful modeling were randomly divided into I/R group and administration group with 60 in each group. All rats in the both groups were observed at five time points, including 6, 12, 24, 48 and 72 hours after reperfusion and after 2-hour ischemia, with 12 experimental animals at each time point. Six rats were prepared for detection of hybridization in situ, and the other 6 were used for Western blotting histochemical detection. Rats in the control group were opened their skin to separate common carotid artery and not treated with line and drugs. In addition, rats in the I/R group were treated with 1 mL saline at 2 hours after focal cerebral ischemia, and then, rats in the administration group were treated with 1 mL (1 g/L) calcitonin gene related peptide at 2 hours after focal cerebral ischemia. ② The expression of NMDAR1 mRNA was detected with hybridization in situ at various time points; moreover, the expression of NMDAR1 protein was measured with Western blotting method at various time points. The results were analyzed with Metamoph imaging analytical system. MAIN OUTCOME MEASURES: The expression of NMDAR1 mRNA and its protein in cortical neurons of rats at various time points. RESULTS: A total of 84 rats were excluded because of non-symptoms, exanimation or death; and then, 132 rats were involved in the final analysis. The expression of NMDAR1 mRNA and its protein in cortical neurons of rats in the control group was 0.205±0.001 and 0.184±0.001, respectively; after I/R, expression of NMDAR1 mRNA and its protein was up-regulated, especially, expression of mRNA at 6, 12, 24, 48 and 72 hours was 0.245±0.003, 0.287±0.004, 0.354±0.008, 0.284±0.002 and 0.217±0.006, respectively; moreover, expression of protein at 6, 12, 24, 48 and 72 hours was 0.222±0.003, 0.261±0.028, 0.311±0.004, 0.259±0.013 and 0.210±0.008, respectively. There was significant difference between the two groups (0.205±0.001, P < 0.01). The expression was up-related in the former 24 hours, reached peak at 24 hours, down-regulated, and decreased to the level of control group at 72 hours. Except 72 hours, the expression of NMDAR1 mRNA and its protein was lower in administration group than that in I/R group at other four time points. In addition, the expression of mRNA at 6, 12, 24, 48 and 72 hours was 0.223±0.005, 0.243±0.001, 0.292±0.002, 0.250±0.003 and 0.213±0.003, respectively; moreover, the expression of protein at 6, 12, 24, 48 and 72 hours was 0.216±0.006, 0.245±0.025, 0.276±0.003, 0.241±0.045 and 0.202±0.013, respectively. There was significant difference at various time points (P < 0.05). CONCLUSION: The expressions of NMDAR1 mRNA and its protein of peripheral cortical neurons are up-related in ischemic area after focal cerebral I/R. Meanwhile, exogenous calcitonin gene related peptide can protect cortical neurons through inhibiting expression of NMDAR1 mRNA and its protein after focal cerebral I/R.

Expression and role of calcitonin gene-related peptide in mouse Aspergillus fumigatus keratitis

AIM: To investigate the expression and role of calcitonin gene-related peptide(CGRP) in the mouse models induced by Aspergillus fumigatus(A. fumigatus). METHODS: C57 BL/6 mice were randomized into a control group and A. fumigatus keratitis group. The cornea photography was assessed under the slit lamp and the clinical score was recorded after infection. Western blot, real-time polymerase chain reaction(PCR) and immunohistofluorescence analysis were applied to detect CGRP expression in cornea of both groups. In vitro, tests were conducted with C57 BL/6 mice macrophages to investigate CGRP expression after interaction with A. fumigatus. Cytokines expression induced by exogenous CGRP and the antagonist CGRP8-37 in A. fumigatus-exposed macrophages was evaluated by real-time PCR and ELISA.RESULTS: The cornea expression of CGRP was significantly elevated in C57 BL/6 mice corneas and macrophages after A. fumigatus infection. After treatment with exogenous CGRP, the levels of interleukin-1β(IL-1β), tumor necrosis factor-α(TNF-α) and IL-6 were reduced, and IL-10 level was increased in the A. fumigatus stimulatedmacrophages. However, IL-1β, TNF-α and IL-6 levels were upregulated after pretreatment of CGRP8-37. But the m RNA levels of MIP-2, TGF-β and IL-10 were not changed. CONCLUSION: This study provides evidence that A. fumigatus increased CGRP expression. CGRP may play a protective role against inflammation in A. fumigatus keratitis.

Co-existence of calcitonin gene-related peptide (CGRP) and 5-hydroxytryptamin (5-HT) in rabbit lung

It was investigated that the localization and distribution of calcitonin gene-relatedpeptide (CGRP) in the rabbit lung by ABC-GDN immunohistochemistry.The results demon-strated that CGRP immunoreactivity was located in neuroendocrine cells (NEC_s) and neu-roepthelial bodies (NEB_s),including all airways from bronchi,bronchioles,and alveolar ducts.The nerve fibers in walls of the intrapulmonary bronchi and blood vessels also had CGRP-immunoreactivity.Adjacent sections immunostained with antibodies to CGRP and 5-HT provedthe coexistence of CGRP and 5-HT in NECs and NEBs.This finding suggested the possibilityof functional interaction between the peptide and amine.

The inhibitory effect of calcitonin gene-related peptide on adriamycin induced acute cardiotoxicity in cultured myocardial cells

Objective: To observe the inhibitory effect of calcitonin gene--related peptide (CGRP) on adriamycininduced acute cardiotoxicity. Methods: Primarily cultured rat myocardial cells were treated with 10-6 mol/Ladriamycin and 10-6mol/L adriamycin + 10 8mol/I. CGRP. Lactate dehydrogenase (LDH ) activity in the mediumand the contents of malondialdehyde (MDA ). calcium. and magnesium in the myocardial cells were assayed.Results: In the adriamycin group, LDH activity in medium and calcium, MDA contents in myocardial cells weresignificantly increased compared with those in control group, and magnesium content in the myocardial cells wassignificantly reduced. In the adriamycin group. there was a positive correlation between LDH activity in themedium and MDA content in the myocardial cells. Meanwhile, in the adriamycin + CGRP group,- CGRP mightsignificantly reduce the leakage of LDH from myocardial cells, lessen the increase in calcium and MDA contentsand prevent the loss of magnesium. Conclusion: CGRP may inhibit adriamycin induced acute cardiotoxicity byinhibiting lipid peroxidation, attenuating calcium overload, magnesium loss, and protecting enzyme activity.

Osteogenic potential of human calcitonin gene-related peptide alpha gene-modified bone marrow mesenchymal stem cells

Background Most of the basic and clinical studies of osteonecrosis of the femoral head （ONFH） are restricted to bone tissues only, whereas various systems are involved in the onset and development of ONFH, including nervous system. Peptidergic nerve participates in the neuronal regulation of bone metabolism and anabolism, and plays key roles in the growth, repair and reconstruction of bone. Calcitonin gene-related peptide （CGRP）, which is secreted by peptidergic nerve, is the main mediator of bone metabolism. It dramatically promotes the proliferation and osteogenic differentiation of bone marrow mesenchymal stem cells （BMSCs）. Additionally, it enhances the osteoblast mass and the rate of osteoblast formation, and reduces the bone resorption by acting on osteoblasts and osteoclasts. Hence, we aimed to construct recombinant retrovirus vector pLNCX2-hCGRPα and to investigate the proliferation and osteogenic potential of hCGRPα-producing BMSCs （BMSCs/pLNCX2-hCGRPα） after virus infection. Methods The constructed recombinant retrovirus vector pLNCX2-hCGRPα was transfected into PT67 packaging cells by lipofectamine 2000. Virus was collected for BMSCs infection. The mRNA and protein expression of hCGRPα was examined by reverse transcription polymerase chain reaction （RT-PCR） and Western blotting, respectively. The cell proliferation was determined by methyl thiazoleterazolium （MTT） assay. The osteogenic potential of BMSCs was evaluated by alkaline phosphatase （ALP） activity. Results Both mRNA and protein expression of hCGRPα was detected in BMSCs/pLNCX2-hCGRPα cells. These cells exhibited significantly elevated proliferation and ALP value as compared with control BMSCs （P 〈0.05）. Conclusion BMSCs/pLNCX2-hCGRPα cells could stably express hCGRPα and showed promoted proliferation ability and osteogenic potential as compared with control BMSCs.

Calcitonin gene-related peptide induces proliferation and monocyte chemoattractant protein-1 expression via extracellular signal-regulated kinase activation in rat osteoblasts

Background Calcitonin gene-related peptide （CGRP）, a sensory neuropeptide, affects osteoblast proliferation and bone formation. However, the mechanisms are not fully understood. Monocyte chemoattractant protein-1 （MCP-1） is a chemokine that stimulates the migration of monocytes and plays important roles in regulating bone remolding during fracture repair. In this study, we investigated the effects of CGRP on proliferation and MCP-1 expression in cultured rat osteoblasts. Methods Primary rat osteoblasts were isolated from fetal rats calvariae. Cells were exposed to gradient concentrations （10^-9 to 10^-7 mol/L） of CGRP. Protein and mRNA levels of MCP-1 were quantified by Western blotting and semiquantitative reverse transcdption-polymerase chain reaction, respectively. The protein level of MCP-1 was investigated and compared in cell culture media by enzyme linked immunosorbent assay （ELISA）. Phospho-extracellular signal-regulated kinase （ERK） expression was detected by Western blotting. Cell proliferative activity was measured by 3-（4,5-dimethylthiazol-2-yl）-2, 5-diphenyl tetrazolium bromide （MTT） and BrdU assay. The effects of MAPK/ERK kinase （MEK）-inhibitor U0126 on CGRP-induced MCP-1 expression in primary rat osteoblasts were examined. Results CGRP effectively enhanced primary rat osteoblast proliferation and led to significant increases in the expression of MCP-1 mRNA and protein in time- and dose-dependent manners. CGRP activated the ERK pathway. Pretreatment of cultured rat osteoblasts with MEK inhibitor U0126 resulted in dose-dependent inhibitions of CGRP-induced MCP-1 mRNA and protein levels. Thus, CGRP promoted cell proliferation and stimulated MCP-1 expression in cultured rat osteoblasts. Conclusion These studies document novel links between CGRP and MCP-1 and illuminate the effects of CGRP in regulating bone remodeling.

Effects of Qindan Capsule (芩丹胶囊) on Blood Pressure, Endothelin, Calcitonin Gene-related Peptide and Angiotensin-Ⅱ in Spontaneous Hypertensive Rats

Objective： To observe the hypotensive effects of Qindan Capsule （芩丹胶囊, QC） on spontaneous hypertensive rats （SHR） and its effect on the contents of endothelin （ET）, calcitonin gene-related peptide （CGRP） and angiotensin-Ⅱ （Ang-Ⅱ ） in plasma and vascular tissues, and to investigate the possible mechanism of QC in lowering blood pressure. Methods： Forty SHRs were divided into 5 groups： the high dosage QC group [QCHD, 750 mg/（kg.d） ], the low dosage QC group [QCLD, 150 mg/（kgd） ], the Niuhuang Jiangya Pill group [牛黄降压丸,, NJP, 200 mg/（kg.d）], the Captopril group [ 15 mg/（kgd）]and the model group, 8 in each group. Meanwhile, a normal control group consisting of 8 Wistar-Kyoto （WKY） rats was set up also. All the rats were administered with medicine level of ET, CGRP and Ang-Ⅱ in plasma and Ang-Ⅱ rats after 12 weeks of treatment. Results： The leve through gastrogavage. Systolic blood pressure （SBP）, in tissues of mesenteric artery were detected in all the of SBP after treatment in the QCHD group was lower than that in the model group （ P〈0.01 ）, but with no significant difference as compared with that in the Captopril group and the NJP group （P〉0.05）. After treatment, the plasma level of ET was lower and CGRP higher than those in the model group （both P〈0.05）, and also higher than those in the NJP and Captopril group （both P〈0.05）. As for the content of Ang- Ⅱ , in mesenteric arterial tissues, it was lower in the QCHD group than that in the model group （ P〈0.05）, but in plasma, it showed no significant difference between the two groups （P〉0.05）. Conclusion： QC has a satisfactory hypotensive action on SHR rats, and its mechanism may be associated with the regulation on plasma vasoactive peptide and regional renin-angiotensin system.