黄芪多糖对糖尿病大鼠微血管病变的作用及机制的研究

目的：探讨黄芪多糖（APS）对糖尿病大鼠微血管病变的影响以及对糖尿病的治疗作用及机制。方法：成年，健康SD大鼠40只，雌雄不限，分成四组：正常对照组，糖尿病组（腹腔注射四氧嘧啶200mg/kg),APS组（造模成功后用APS治疗），优降糖组（造模成功后用优降糖治疗）。治疗两周时测一次血糖，四周后，测血糖；颈动脉取血测定血清胰素水平，NO和MDA含量。应用形态定量的方法比较各组的心肌病理变化。结果：腹腔注射alloxan(200mg/kg)后的SD大鼠血糖浓度显升高，血清NO，MDA，胰岛素水平明显改变。APS治疗四周后，血糖浓度明显下降，与优降糖治疗组无明显差异，血清NO较未治疗组明显升高（P＜0．01），血清MDA较未治疗组明显减少（P＜0．01），血清胰岛素水平升高（P＜0．05），光镜下观察，糖尿病大鼠的心肌毛细血管数量减少，基底膜增厚，微血管与心肌纤维的比率显减低，这些改变都可被APS改善.结论：APS有降低血糖和保护血管内皮细胞的作用，这可能与APS减轻氧自由基的损伤，影响NO的产生以及促进胰岛B细胞的损伤的恢复有关。

Effect of Astragalus Polysaccharide on Pathologic Change of Micrangium of Diabetic Rats and Experimental Study on the Mechanism

To investigate the effect of astragalus polysaccharide(APS) on pathology of diabetic microvessel.Methods:We randomly divided 40 SD rats into four groups;control group,diabetes mellitus group(diabetic model rat induced by alloxan),APS group,glybenzcyclamide group.After having been doctored for 4 weeks,the rats were killed and their blood was withdrawn by carotid artery catheter and used to measure the levels of glucose,serum insulin,NO and MDA.Myocardiac pathologies of each group were used for morphometric studies.Results:Compared with control group,the levels of glucose,MDA,NO and ins were changed significantly,After administration of APS,the levels of Glu,MDA decreased and the levels of NO,ins increased in diabetic model groups.Under the microscope,the capillary density and the ratio of capillary to myofibre in DM rats were reduced remarkably compared with control gruop.The capillary basement membrane in DM rats was thicker.These alterations could be amended by APS.Conclusion:APS has the functions of protecting the vessel endothelial cells of diabetes mellitus.