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BACKGROUND:Ghrelin is a newly discovered brain-gut peptide from the stomach of human and rats. As an endogenous ligand for growth hormone secretagogue receptor (GHSR), ghrelin can notably stimulate the release of growth hormone. Although GHSR is expressed in many peripheral tissues, little is known about the influence of ghrelin on bone metabolism and GHSR expression in bone tissue. OBJECTIVE:To review the research progress of ghrelin in bone metabolism.METHODS:The first author retrieved CNKI, WanFang, PubMed, and Springerlink databases with the keywords ofGhrelin, bone metabolismin Chinese and English, respectively. The studies regarding ghrelin and its involvement in bone metabolism were included, and repetitive ones were excluded. A total of 53 eligible literatures were selected through skimming abstracts. RESULTS AND CONCLUSION:Ghrelin is a peptide composed of 28 amino acids discovered in gastric endocrine cells and hypothalamic arcuate nucleus in mice and human, which makes a great effect on digestive, nervous, immune and endocrine systems, and also plays a role in hormone secretion, glucose metabolism, immunity, cell proliferation, and inflammation. Serum ghrelin makes a certain influence on bone growth and development, and promotes the differentiation and proliferation of osteoblasts, and inhibits its apoptosis. Additionally, ghrelin suppresses the early osteogenic differentiation of C3H10T1/2 cells by upregulating the expression of Runx2 protein, and attenuates adipogenic differentiation by downregulating PPARγ2 expression, thus inducing osteogenic differentiation. However, few studies have addressed the expression of GHSR in bone tissue.
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Objective To investigate the effect of drugs in combination with rehabilitative training on motor function and the expression of survivin in the ischemic penumbra after focal cerebral ischemia.Methods One hundred and twenty male,adult,Sprague-Dawley rats were subjected to left middle cerebral artery occlusion (MCAO)by suturing.Ninety-six of them were then randomly divided into a control group,a drug group,a rehabilitative trainiug group,and a drugs in combination with rehabilitative training group,with 24 in each.For three days the rats in the control group received no treatment,while those in the drug group received 500 mg/kg of citicoline daily,those in the rehabilitative training group received motor training including balancing,grasping,rotating and walking exercises,aud those in the drug and rehabilitative training group received both citicoline and the motor training.Behavioral tests were administered to all groups,and immunohistochemistry was used to detect the expression of survivin in the ischemic penumbra.Results Average behavior scores in the drug group and the control group were not significantly different at day 7,14 or 21 after the MCAO.Average behavior scores in the rehabilitative training and drug in combination with rehabilitative training groups were significantly superior to those of the control and drug groups at day 14 and 21.At those time points the average scores in the drug in combination with rehabilitative training group were also significantly better than those of the rehabilitation training group.Compared with control group,at the 7th,14th and 21st day after MCAO,expression of survivin in the other three groups had increased significantly.Expression of survivin in the group where drug treatment was combined with rehabilitative training was significantly greater than in the drug and rehabilitative training groups.Conclusions Citicoline in combination with rehabilitative training can improve the recovery of motor function in rats significantly better than the other approaches.This might be partially attributed to the up-regulation of survivin expression in the peri-ischemic cortex.
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Objective To investigate the effects of citicoline combined with rehabilitative training on motor function after focal cerebral ischemia. Methods One hundred and twenty male adult Sprague-Dawley rats ( 3 months old) were subjected to left middle cerebral artery occlusion (MCAO) by suturing. Ninety-six of them were randomly divided into four groups of 24: a control group, a drug group, a rehabilitative training group, and a drug combined with rehabilitative training group. The rats in the control group did not receive any treatment. Three days after reperfusion, those in the drug group received 500 mg/kg of citicoline daily; those in the rehabilitative training group received motor training including balancing, grasping, rotating and walking exercises; those in the combined group received both citicoline and the motor training program. Behavioral tests were administered at the 7th, 14th and 21st days after MCAO. At the same time points, immunohistochemistry was used to detect calcium-binding protein S100 and β-tubulin expression in the peri-ischemia region of the cortex. Results ①As compared with the control group, the drug group at the 7th, 14th and 21st day after MCAO and the other two groups at the 7th day after MCAO showed no significant difference in average behavior scores. But at the 14th and 21st day the rehabilitative training group as well as the drug combined with rehabilitative training group had average behavior scores significantly superior to those of the control group, especially in the drug combined with rehabilitative training group. ②As compared with the control group, the expression of S100 and β-tubulin in the drug and rehabilitative training groups at the 7th day after MCAO showed no significant difference. In the drug combined with rehabilitative training group the average score was significantly higher than in the other groups at the 7th day after MCAO. All the other groups had average scores significantly higher than that of the controls at the 14th and 21st day after MCAO, especially the drug combined with rehabilitative training group. Conclusions Citicoline combined with rehabilitative training can significantly improve motor function recovery in rats. The effect of the combined modalities was more obvious, and the functional enhancement might be partially attributable to the up-regulation of S100 and β-tubulin in the cortex.
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Objective To study the effects of uhrashortwave and low frequency pulsed electromagnetic fields on the expression of vascular endothelial growth factor(VEGF) in fracture healing. Methods Fifty-six New Zeal-and rabbits with artificial fractures were randomly divided into 4 groups:a control group,an ultrashortwave group,a low frequency pulsed electromagnetic field group and an ultrashortwave combined with low frequency pulsed electro-magnetic field group(combined group),with 14 in each group.Radiographic evaluation of callus formation and frac-ture healing,pathohistological examination and detection of VEGF expression through immunohistochemical staining were performed at the 1 st,2nd,4th and 6th week after the operation. Results Radiographic examination showed that there was significantly greater callus formation in the combined group than in the other groups throughout the healing process. Pathohistological examination also revealed significantly more cartilage islets and callus formation in the combined group.At the 1 st,2nd and 4th week after the operation,VEGF positive indexes in the combined group were significantly higher than in the other groups. Conclusion Uhrashortwave combined with low frequency pulsed electromagnetic field exposure can up-regulate the expression of VEGF and thus can accelerate fracture healing.