Effects Of Insulin-like Growth Factor-1 In High Glucose Condition On Rat Islet Cells Function And Apoptosis

Objective:To investigate effects of insulin-like growth factor-1 in high glcose condition on rat islet secretion and islet cells apoptosis.Methods:SD rat pancreatic islets were isolated and divided into three groups,control group(glucose5.6mmol/l),high glucose group(glucose 15.6mmol/l),IGF-1 group(glucose 15.6mmol/l+IGF-1 10ng/ml),according to cultured condition.After culturing 48 hours,islets were detected that:the insulin's secretion were evaluated by the radio-immunity technique and the immunohistochemical techniques;Apoptotic cells were identified by Hoechst33342 immunofluorescence techniques and TUNEL method and electron microscope,were evaluated the expression of Bcl-2 by the immunohistochemical techniques.Results:The high glucose group's insulin levels and the expression rates of insulin were significantly lower than the control group(P＜0.05);The apoptotic rates of that were markedly higher than the control one(P＜0.05);The high glcose one's expression rates of Bcl-2 were significantly lower than the control one;The Hoechst33342 immunofluorescence showed there were many chip and pyknosis's cell nucleus in high glcose group;The electron microscope observated the cells ultramicrostructure that the chromatospherite disappeared,the nuclear membrane disfigurated,the quantity of secretory granule were markly lower than the control one.The IGF-1 group's insulin levels and the expression rates of insulin were significantly higher than the control group and the high glucose group(P＜0.05);The apoptotic rates of IGF-1 one were markly higher than the high glucose group(P＜0.05)and significantly lower than the control group(P＜0.05);The IGF-1 one's expression rates of Bcl-2 were markly higher than the high glucose one(P＜0.05)and significantly lower than the control one.The Hoechst33342 immunofluorescence showed the cell nucleus were integrated,there were little chip and pyknosis's ones;The electron microscope observated the IGF-1 one's appearance and constitution were normal the quantity of secretory granule were markly higher than the high glucose one.Conclusion:The IGF-1 can directly action on islet,can simulate insulin secretion,can reduce the apoptotic rates which were inducted by high glucose.The function may on account of the high expression of Bcl-2.