黄芪多糖对糖尿病大鼠胰岛β细胞超微结构及Fas表达的影响

Effects of astragalus polysaccharides on the ultrastructure and Fas expression of pancreatic beta-cells in diabetes mellitus rats

目的观察黄芪多糖(astragalus polysaccharides,APS)对糖尿病(diabetes mellitus,DM)大鼠胰岛β细胞超微结构及Fas表达的影响。方法采用链脲佐菌素(streptozotocin,STZ)55mg·kg-1腹腔注射建立DM大鼠模型,实验分4组:正常组、DM组、APS低剂量组和APS高剂量组,后两组于模型成功后应用APS200、400mg·kg-1.d-1腹腔注射6wk,免疫组织化学法观察胰岛β细胞Fas的表达,电镜观察胰岛β细胞超微结构。结果①正常大鼠胰岛β细胞Fas表达呈弱阳性,DM组大鼠β细胞Fas表达则呈强阳性,APS低剂量组和高剂量组大鼠β细胞Fas的表达较DM组明显减少(P<0.05)。②DM组大鼠胰岛β细胞超微结构呈明显退行性变,APS可明显改善其超微结构。结论 APS治疗糖尿病的作用机制可能与减少胰岛β细胞Fas过高表达,抑制β细胞凋亡有关。

Aim To observe the effects of astragalus polysaccharides（APS） on the ultrastructure and Fas expression of pancreatic beta-cells in diabetes mellitus（DM） rats.Methods Thirty DM rats induced by streptozotocin （STZ） were randomly divided into three groups：DM group,APS 200 mg·kg^-1·d^-1 group,APS 400 mg·kg^-1·d^-1 group,another 10 normal rats were taken as the control group. The drug was given by intraperitoneal for 6 weeks. The protein expression of Fas was observed by immunohistochemistry. The TEM was used to observe the ultrastructure of pancreatic beta-cells. Results ① The expression of Fas of beta-cells was significantly increased in DM rats,which was significantly inhibited by APS treatment. ② It showed degenerative changes in the ultramicroscopic structure of pancreatic beta-cells of DM rats,while APS treatment could significantly improve the damage. Conclusion APS exerts its therapeutic effects on DM,which may be related to the significant decrease of the Fas expression and inhibiting the apoptosis of beta-cells.