Ghrelin对离体大鼠胰岛分泌胰岛素的影响及其机制  

Influence and mechanism of ghrelin on insulin release in isolated rat islets

作　　者：周晓磊[1] 薛承锐[1] 

机构地区：[1]天津医科大学总医院中西医结合外科,300052

出　　处：《中华实验外科杂志》2011年第2期212-214,共3页Chinese Journal of Experimental Surgery

摘　　要：目的 观察外源性Ghrelin对胰岛素分泌和胰岛内向整流钾通道（Kir6.2）表达的影响.方法 Wistar大鼠按10 nmoL/kg的剂量予Ghrelin腹腔注射2周后,分离胰岛进行胰岛素释放实验,分离β细胞检测静息膜电位;检测胰岛Kir6.2 mRNA和蛋白表达变化.结果 在11.1、16.7mmol/L葡萄糖刺激下,对照组的胰岛素释放分别为22.5、43.5 uIU/胰岛/h,Ghrelin组为15.2、30.1uIU/胰岛/h,较对照组显著降低（P＜0.05）.对照组β细胞的静息膜电位为（-73.2±24.8）mV,Ghrelin组为（-95.4±33.7）mV,较对照组显著降低（P＜0.05）.而Ghrelin组Kir6.2表达显著高于对照组（P＜0.05）.结论 Ghrelin与其受体结合后抑制胰岛素分泌,其机制可能与上调Kir6.2表达,使β细胞兴奋性降低有关.Objective To investigate the influence of ghrelin administration on the insulin secretion, and the expression of Kir6. 2 channels in islets. Methods Ghrelin was intraperitoneally administrated in Wistar rats at the doses 10 nmol/kg every day for 2 weeks. Islets were isolated for insulin release experiments. Single β cells were isolated for electrophysiological experiments. Meanwhile, the expression levels of Kir6. 2 mRNA and protein in islets were detected. Results At 11. 1 and 16. 7 mmol/L glucose,the levels of insulin release in control group were 22. 5 and 43.5 uIU/islet per h, and those in ghrelin-treated group were 15. 2 and 30. 1 uIU/islet per h （P 〈0. 05 ）. In control group, the resting membrane potential reached （ - 73.2 ± 24. 8 ） mV, but in ghrelin-treated group, it was hyperpolarized to （ - 95.4 ± 33.7 ）mV （ P 〈 0. 05 ）. The Kir6. 2 expression levels were significantly up-regulated by ghrelin （ P 〈 0. 05 ）.Conclusion Ghrelin via pancreatic GHSR up-regulates the Kir6. 2 expression in islets, hyperpolarizing the resting membrane potential, and resulting in the inhibition of insulin release.

关 键 词：GHRELIN 胰岛素 内向整流钾通道 

分 类 号：R587.1[医药卫生—内分泌]