苦荞提取物对2型糖尿病大鼠胰岛细胞凋亡的干预作用

目的：探讨苦荞提取物对2型糖尿病大鼠胰岛细胞凋亡的干预作用.方法：Sprague-Dawley大鼠分为6组：正常对照组、模型组、二甲双胍组、苦荞提取物低、中、高剂量组.模型组和给药组采用高脂高糖诱导饮食.两周后,腹腔一次性注射链脲佐菌素（STZ,30 mg·kg^-1）建立大鼠2型糖尿病模型.二甲双胍组给予300 mg·kg^-1剂量灌胃,苦荞提取物组分别给予250 mg·kg^-1、500 mg·kg^-1、1 g·kg^-11苦荞提取物灌胃.给药4周后,检测大鼠空腹血糖值和空腹血清胰岛素（FINS）值,处死大鼠,取大鼠胰脏组织,H＆amp;E染色观察形态学变化;TUNEL法观察胰岛细胞凋亡;免疫组织化学法检测细胞死亡信号转导效应酶caspase-3在胰岛中的表达.结果：与模型组比,苦荞提取物组可显著降低大鼠空腹血糖值和空腹FINS值（P〈0.05）.HE结果显示苦荞提取物组和二甲双胍组大鼠胰岛形态未出现明显缩小及胰岛细胞减少情况,TUNEL结果显示苦荞提取物组与二甲双胍组胰岛中胰岛细胞凋亡均明显减少,caspase-3结果显示苦荞提取物组和二甲双胍组中caspase-3表达均有下调趋势（P〈0.05）.结论：苦荞提取物能够有效降低STZ诱导2型糖尿病大鼠胰岛细胞的凋亡.

Intervening Effects of Tartary Extracts on Apoptosis of Islet Cells in Type 2 Diabetic Rats

Objective： To investigate the protective effects of tartary extracts on islet cells in type 2 diabetic rats induced by STZ. Methods： Sprague Dawley rats were divided into six groups, the normal contrd group, model group, metformin hydrochloride （DM） group and three tartary extracts （TE） groups. The rats in the model group, DM group and the three TE groups were raised with high fat and high glucose food, and received intraperitoneal injection of STZ （30 mg·kg^-1 ） after 2 weeks. Then the rats in the DM group were received 300 mg·kg^-1 DM and the TE groups were respectively given 250,500 mg ·kg^-1 and 1 g·kg^-1 TE for 4 weeks. The fasting blood glucose and FINS of the rats were tested. The rats were sacrificed after the drug treatment, and the apoptosis of islet ceils was de- termined by TUNEL assay and the expression of caspase-3 in pancreatic tissue was measured using an immunohistochemical staining. Results： Compared with that of the model group, HE photo of the TE and DM group showed that the area of pancreas isle and the num- ber of cell nucleus in pancreas isle were increased. Caspase-3 and TUNEL expression of the TE and DM group were significantly de- creased compared with that of the model group. Conclusion： Tartary extracts can significantly decrease the death of islet cells in type 2 diabetic rats induced by STZ.