The Research Of Various High-dose Glucose Cause Cell Apoptosis And Change GLUT2/IRS-1/IRS-2 MRNA Expression In Isolated Rat Pancreatic Islet Cells

Part one The mechanism of various high-dose glucose cause cell apoptosis in isolated rat pancreatic islet cellsObjective To research the effects of various high-dose glucose cause cell apoptosis in isolated rat pancreatic islet cells.Methods Islet cells were obtained by Collagenase P digestion and Ficoll-400 density gradient purification from Adult SD rat pancreas, which was cultured in RPMI-1640 culture media for 2 days.Then they were treated with various high-dose glucose for 5 days. The insulin concentrations in the supernatant were measured by Radioimmuno-assay (RIA) . The morphology of cells were observed when they were stained by AO/EB. Cell apoptosis rates were calculated by Tunel Kit. Total RNA of islets were abstracted by TRIzol reagent. The levels of bcl-2 and bax mRNA were measured by reverse transcription polymerase chain reaction (RT-PCR).Results Insulin concentrations increased in 11.1mmol/L glucose group and 22.2 mmol/L glucose group (P<0.05), but there were no difference between them(P>0.05). Insulin concentration decreased in 26.7mmol/L glucose group. High dose glucose caused islets apoptosis.There were islet necrosis in 26.7mmol/L glucose group. Decreased bcl-2 level and increased bax level were detected in three high-dose glucose groups(P<0.05),but there were no difference among them(P>.0.05). Conclusions (1), Islets apoptosis increased in ll.lmmol/L glucose group,22.2 mmol/L glucose group and 26.7mmol/L glucose group. (2),Islets necrosis was detected in 26.7mmol/L glucose group. (3),The mechanism of apoptosis in high-dose glucose may be related to the increasing bax mRNA level and the decreaing bcl-2 mRNA level.