摘要
目的:探索不同浓度葡萄糖引起胰岛细胞凋亡的机制. 方法:用胶原酶P消化Ficol1400纯化的成年SD大鼠胰岛细胞,经RPMI1640培养7天后铺成单层,分别设立对照组和不同浓度的葡萄糖组,用放免法测定加葡萄糖后1、3、5、7、9和11天胰岛素浓度.用流式细胞术测定加处理因素后11天的胰岛细胞凋亡率和免疫组化法测定bax及bcl-2蛋白的表达.另取单层培养的胰岛细胞,亦设立对照组和加入不同浓度甘露醇组,培养11天后,用免疫组化法测定bax和bcl-2蛋白的表达,流式细胞术测定胰岛细胞凋亡率. 结果:①葡萄糖为11.1mmol/L时,胰岛素浓度开始升高;当葡萄糖升至22.2mmol/L时达高峰,且随时间延长而下降.②葡萄糖为11.1和22.2mmol/L时,胰岛细胞凋亡率最高, 5.5mmol/L组与对照组的凋亡率差异无显著性意义.甘露醇组胰岛细胞的bax及bcl-2蛋白表达与对照组比较无显著差异,胰岛细胞凋亡率与对照组比较亦无著著差异.③葡萄糖在11.1～22.2mmol/L时,bax蛋白表达阳性,bcl-2蛋白表达阴性,葡萄糖在33.3mmol/L时,bax和bcl-2蛋白的表达匀为阴性,5.5mmol/L组bax和bcl-2蛋白的表达与对照组无显著差异. 结论:高血糖(葡萄糖为11.1和22.2mmol/L)可引起胰岛细胞凋亡和胰岛素释放增加,当葡萄糖浓度升至33.3mmol/L时,胰岛细胞凋亡率开始下降,胰岛素释放也减少.表明高渗状态与高血糖诱导的胰岛细胞凋亡无关.
Objective：To explore the mechanism of islet cell apoptosis caused by glucose at different concentrations. Methods：The islet cells of SD adult rats were prepared by collagenase digestion, purified by Fcol1400 and cultured in RPMI1640. Different concentrations of glucose or mannitol were added into the monolayer of islet cells. The medium insulin concentration was measured by RIA. The apoptosis rate was measured by the flow cytometry and the bax and bcl-2 expressions were detected by immunoblot. Results ：①With glucose concentration raised from 11.1 mmol/L to 22.2 mmol/L, the insulin concentration began to raise and reached the peak, then it 22.2 mmol/L, the apoptosis rate was the highest, began to decline. ②With glucose at 11.1 mmol/L and while at 5.5 mmol/L, there was no significant difference compared with the controls. For the groups of mannitol-infused, there was no differences of bax or bcl-2 expressions and no difference of the apoptosis rate comparing with the controls. ③With glucose infused, the bcl-2 expressions in 11.1 mmol/L and 22.2 mmoL/L groups were negative, bax expression was positive ; the bax and bcl-2 expressions were negative in the group of 33.3 mmol/L; the bax and bcl-2 expressions in the 5.5 mmol/L group showed no difference compared with the controls. Conclusion ： Higher levels of glucose at 11.1 mmol/L and 22.2 mmol/L lead to the release of more insulin and the raise of apoptosis rate. But with glucose concentration at 33.3 mmol/L, the release of insulin decreased and the apoptosis rate declined. Hyperosmolality could not cause the apoptosis of the islet cell.
出处
《医学研究生学报》
CAS
2005年第10期882-885,i0007,共5页
Journal of Medical Postgraduates
基金
湖南省教委科研基金资助项目(批准号:96159)
关键词
高血糖
胰岛细胞
凋亡
High glucose
Islet cells
Apoptosis
