胰高血糖素样肽-1对胰岛β细胞功能的影响

目的观察胰高血糖素样肽-1（glucoincretin hormone glucagon-likepeptide-1，GLP-1）对RIN-m细胞分泌功能的影响。探讨GLP-1对链脲佐菌素诱导胰岛细胞凋亡的保护机制。方法应用TUNEL法检测RIN-m细胞凋亡的百分率；RT—PCR检测PDX-1，bcl-2／baxmRNA的表达。结果GLP-1在高糖培养下可以延缓RIN-m细胞随体外培养时间延长而出现的胰岛素和胰十二指肠同源盒基因转录因子1（PDX-1）．RNA水平的下降，且其作用具有葡萄糖依赖性。GLP-1可以保护低剂量链脲佐菌素使RIN—m细胞凋亡细胞比例明显减少，凋亡过程中，baxmRNA表达水平明显降低，bcl-2mRNA表达水平明显上升。结论由此推测GLP—1可能通过PDX-1延缓RIN—m细胞胰岛素分泌功能的下降，同时GLP＋1可以保护低剂量链脲佐菌素通过诱导胰岛细胞凋亡导致糖尿病，其中bcl＋2／baxmRNA表达比率变化可能起重要作用。

GLP-1 is Effect on Function of the Pancreatic Beta Cell

Objective To investigate the effect of the glucagons-like peptide-1(GLP-1) on RIN-m cells in high level of glucose and its related gene regulation and the relationship between the former two,to explore protect mechanism of GLP-1 when low dose of streptozotocin induce islet cells apoptosis. Methods Apoptosis ratio in RIN-m cells cultured by low dose of streptozotocin was conform by TUNEL.The mRNA expression of bcl-2 and bax in cultured cells was conformed by quantity RT-PCR. Results GLP-1 can delay decreasing the level of insulin and PDX-1 RNA of RIN-m cell cultured by high glucose,and became time-dependent in vivo and glucose-dependent. GLP-1 can descend apoptosis ratio of RNA-m cell induced by low dose of streptozotocin. During apoptosis process level of bax mRNA decreased sufficiently,but level of bcl-2 mRNA increased obviously. Conclusion GLP-1 may delay decreasing of insulin in RIN-rn cells by PDX-1,and GLP-1 could interrupt progress of diabetes diseases which developed by islet cells apoptosis induced by low dose of streptozotocin,and the ratio of bcl-2/bax mRNA may play an importent role.