南瓜多糖对糖尿病大鼠胰岛Fas、Fas-L、Bcl-2及Bax表达的影响

Effects of pumpkin polysaccharide on Fas、Fas-L、Bcl-2 and Bax expression in the pancreas of diabetic rats

目的观察南瓜多糖(PP)对链脲佐菌素(STZ)诱导的糖尿病大鼠胰腺组织中Fas、Fas-L、Bcl-2及Bax表达的影响。方法建立链脲佐菌素性糖尿病模型,PP(150、300、600mg.kg-1)灌胃进行治疗。3wk后检测大鼠空腹血糖值;采用免疫组化的方法探讨PP对链脲佐菌素性糖尿病大鼠Fas和Fas-L蛋白表达的影响;采用RT-PCR的方法观察PP对实验性糖尿病大鼠胰岛凋亡调控基因Bax和Bcl-2表达的影响。结果PP(300、600mg.kg-1)能明显降低STZ诱导的糖尿病大鼠的空腹血糖值;PP(150、300、600mg.kg-1)治疗后大鼠胰腺组织中Fas/Fas-L蛋白的表达率明显低于STZ模型组;PP(150、300、600mg.kg-1)给药3wk后,大鼠Bcl-2基因的表达明显增加,PP(300、600mg.kg-1)治疗后大鼠Bax基因的表达明显下降,Bcl-2与Bax的比值明显增加。结论PP对实验性糖尿病大鼠有降血糖作用,其作用与降低大鼠胰腺组织中Fas、Fas-L蛋白的表达、调节Bcl-2与Bax基因的表达有关。

Aim To investigate the effects of pumpkin polysaccharide （PP） on Fas,Fas-L,Bcl-2 and Bax expression in the pancreas of diabetic rats. Methods Rats were injected intraperitoneally （ip） with streptozocin （STZ） 60 mg · kg^-1 to induce diabetic model.The diabetic rats were given PP 150 mg · kg^-1,300 mg· kg^-1,600 mg·kg^-1. The blood sample were taken after three weeks. Blood glucose was measured by glucose oxidase method; The expression of the Fas and Fas-L have been determined by using immunohistochemistry （S-P method） ; The expression of Bax mR- NA and Bcl-2 mRNA were checked up by Reverse transcription PCR （RT-PCR）. Results PP could decrease the level of blood glucose in streptozotocin-induced sions duced diabetic rats; After three weeks, The expresof the Fas and FasL in β cell of streptozotocin-indiabetic rats were obviously lower; The expression of Bax mRNA was obviously down-regulated, the expression of Bcl-2 mRNA was obviously up-regulated, and the ratio of Bcl-2/Bax was advanced after the diabetic rats were given PP. Conclusions PP could decrease the level of blood glucose of the diabetic rats. The mechanism was related to decreasing the expressions of the Fas and FasL and regulating the expressions of Bcl-2 and Bax in the pancreas of diabetic rats.