| Objective: The novel peptide nesfatin-1 and GLP-1 have been implicated in feeding and energy homeostasis. This study was designed to observe the the expression of nesfatin-1in paraventricular(PVN) and other digestive organs after the third ventricle injection GLP-1and to elucidate upstream or downstream molecular mechanism between GLP-1 and nesfatin-1. To explore the potential regulatory mechanisms in the progress of gastric motility between these two peptides after the central injection GLP-1 or anti-nesfatin-1 antibody.Methods: The expression of the NUCB2 m RNA in the PVN by q RT-PCR after administrate different doses of GLP-1(1ng,10 ng,100ng),saline and exendin(9-39)+10ng GLP-1(E+G) by the third ventricle cannule. Then we compared the expression of NUCB2/nesfatin-1 protein in the PVN by immunohistochemical staining between different doses of GLP-1(1ng,10 ng,100ng) group, NS group and E+G group. In peripheral, we compared these variables change of NUCB2 m RNA in the stomach, pancreases small intestinal and colon after administration saline,10 ng GLP-1 and E+G by the third ventricle cannula. The different distribution of NUCB2/nefatin-1 proteins were observed by immunohistochemical staining. Two groups of rats respectively give saline,10 ng GLP-1 in the third ventricle, another group pretreatement with anti-nesfatin-1 antibody in the PVN before give 10 ng GLP-1 in the third ventricle, then assess their gastric emptying by a modified phenol red-methylcellulose recovery method.Results: The q RT-PCR showed that a significantly higher expression of NUCB2 m RNA in the PVN of different doses of GLP-1 group than NS group in a dose-dependent manner.However, the amount of nesfatin-1 positive cell in the PVN increased in the 10 ng and 100 ng GLP-1 groups compare with NS group(P<0.05) in the immunohistochemistry study. The expression of nesfatin-1 m RNA and nesfatin-1/NUCB2 proteins have no correlation between NS group, 10 ng GLP-1 group and E+G group in stomach, pancreas, small intestinal and colon respectively(P>0.05). Central injections of GLP-1 inhibit gastric emptying in rats compared with NS group(P<0.01), but this effect can be decreased in some extent by pretreatment with anti-nesfatin-1 antibody.Conclusions: The experimental results reveal that GLP-1 can increase the expression of NUCB2/nesfatin-1 in the PVN, but have no difference in digestive organs. Meanwhile we find that nesfatin-1 may take part in GLP-1 mediated inhibition gastric emptying. |
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