胰高糖素样肽1对大鼠胰岛功能影响的研究

Study on the effect of glucagon-like peptide 1 on the functions of rat pancreatic islets

目的:研究胰高糖素样肽-1(GLP-1)对大鼠胰岛功能的影响,探讨GLP鄄1在糖尿病治疗中的作用。方法:①GLP鄄1(10nmol/L)与原代培养的大鼠胰岛共孵育1天、3天和5天后,分别行葡萄糖刺激下的胰岛素分泌试验(GSIS),在试验的0、10、20及60min依次收集细胞培养上清液,放免法检测胰岛素水平的变化。或与GLP鄄1共育1天、3天、5天后分别收集各组胰岛细胞,RT鄄PCR法检测各组胰岛素基因表达的变化。②分别予不同浓度的GLP鄄1(0、1、10、102和103nmol/L)与大鼠胰岛细胞瘤细胞RINm5f共育24h,及GLP鄄1(10nmol/L)与RINm5f共育24h、48h及72h,MTT法检测各组A值变化。结果:①与GLP鄄1共育后,大鼠胰岛基础胰岛素分泌量增加(P<0.05),GSIS试验中各时间点胰岛素分泌量均升高(P<0.05),胰岛素基因的表达量呈时间依赖性升高,即予GLP鄄1刺激5天后,胰岛素基因表达量最高;②与GLP鄄1共育后,随GLP鄄1浓度的增高及刺激时间的延长,RINm5f细胞MTT法中A值呈剂量及时间依赖性的增加。结论:GLP鄄1可促进大鼠胰岛细胞胰岛素基因的表达和蛋白的分泌,对大鼠胰岛细胞亦有明显的促增殖作用。

Objective: To investigate the effect of glucagon-like peptide 1 on the functions of rat pancreatic islets. Methods: ① Purified rat pancreatic islets were divided into three groups and cultured with or without GLP-1 for 1, 3, and 5 days. At the end of Day 1, 3, or 5, a glucose-induced insulin secretion test was performed, and the supernatants were collected to examine the insulin levels or the cellular pellets were collected to test the mRNA levels of insulin gene; ②Rat insulinoma cell line RINm5f was cultured with different concentrations of GLP-1 for various periods, and the OD values of each group were determined by MTT method. Results: ①After co-cultured with GLP-1, both the baseline and glucose-stimulated insulin production were increased compared to the control groups, and the expression of insulin gene level was also enhanced in GLP-1 groups; ② After co-cultured with GLP-1,the OD values were elevated in a dose and time-dependent manner. Conclusion: GLP-1 can not only increase the insulin gene expression and insulin secretion, but also stimulate the proliferation of islet cells.