黄芪多糖对糖尿病心肌病变仓鼠心肌胶原表达的影响

Effect of astragalus polysaccharides on the expression of myocardial collagen in hamsters with diabetic cardiomyopathy

目的:观察黄芪的有效成分之一黄芪多糖对链脲佐菌素诱导糖尿病心肌病变仓鼠物质代谢及心肌胶原代谢的影响,进而探讨黄芪多糖对糖尿病心肌病变的治疗价值及可能机制。方法:实验于2002-06/2003-06在复旦大学上海医学院病理教研室完成。选用普通级8周龄雄性仓鼠30只。黄芪多糖由原中国科学院上海生理学研究所提供。①选用6只为正常对照组:正常饲养,不予特殊处理。其余24只仓鼠禁食12h后,腹腔注射10g/L链脲佐菌素溶液,剂量为40mg/kg,连续3d。用血糖仪测定尾尖血血糖,血糖稳定7d后,选用血糖>13.5mmol/L仓鼠12只为糖尿病造模成功者,将其随机分为2组:模型组(每天予1mL生理盐水灌胃)和黄芪多糖治疗组(按1g/kg剂量将黄芪多糖稀释成1mL生理盐水灌胃),每组6只。实验持续10周。②实验10周后采用全自动生化分析仪测定血清三酰甘油、总胆固醇、低密度脂蛋白胆固醇、高密度脂蛋白胆固醇和糖化血清蛋白水平。放免法测定血清胰岛素水平。采用亲和素-生物素-过氧化物酶复合物法检测心肌Ⅰ,Ⅲ型胶原含量,以免疫组化阳性指数(灰度均值×阳性面积百分比)。采用放免法测定血浆、心肌局部血管紧张素Ⅱ。③计量资料差异比较采用t检验。结果:造模失败脱失12只,最终进入结果分析18只。①造模后模型组和黄芪多糖治疗组仓鼠血糖水平均明显高于正常对照组(P<0.01)。实验10周后黄芪多糖治疗组血糖水平明显低于模型组(P<0.01);模型组和黄芪多糖治疗组仓鼠血清胰岛素水平均明显低于正常对照组(P<0.01),且模型组与黄芪多糖治疗组比较,差异不明显(P>0.05)。②实验10周后,模型组仓鼠血清三酰甘油、总胆固醇及低密度脂蛋白胆固醇水平明显高于正常对照组(P<0.05～0.01),而高密度脂蛋白胆固醇水平差异不明显(P>0.05)。黄芪多糖治疗组血清三酰甘油水平明显低于模型组(P<0.05)。③实验10周后,模型组仓鼠心肌Ⅰ和Ⅲ型胶原表达和Ⅰ/Ⅲ型胶原明显高于正常对照组(P<0.01)。黄芪多糖治疗组仓鼠心肌Ⅰ型胶原表达和Ⅰ/Ⅲ型胶原明显低于模型组(P<0.05)。④实验10周后,模型组仓鼠血浆血管紧张素Ⅱ水平和心肌局部血管紧张素Ⅱ含量明显高于正常对照组(P<0.01)。心肌局部血管紧张素Ⅱ含量明显低于模型组(P<0.05)。结论:黄芪多糖可改善糖尿病心肌病变仓鼠心肌胶原沉积,其对心肌病变的治疗机制可能与改善物质代谢及减少心肌局部血管紧张素Ⅱ的生成有关。

AIM： To observe the effects of astragalus polysaccharides on substance metabolism and myocardial collagen metabolism in hamsters with diabetic cardiomyopathy induced by streptozotocin so as to investigate the therapeutic value and possible mechanism of astragalus polysaccharides on diabetic cardiomyopathy. METHODS： The experiment was performed in the Department of Pathology, Shanghai Medical College of Fudan university from June 2002 to June 2003. Thirty male hamsters aged 8 weeks of ordinary grade were selected. Astragalus polysaccharides was provided by Shanghai Institute of Physiology of Academia Sinica. ①Six hamsters were selected as normal control group： Hamsters received normal feeding without special handling. Rest 24 ones received intrapedtoneal injection of 10 g/L streptozotocin solution 12 hours after fasting at the dose of 40 mg/kg for 3 continuous days. Blood glucose in tail-points were assayed with blood glucose monitor. Seven days after glucostasis, 12 hamsters with the blood glucose above 13.5 mmol/L were considered as successful diabetic models and randomly divided into 2 groups： Model group （hamsters were treated with gastric peffusion of 1 mL normal saline per day） and astragalus polysaccharides treatment group （hamsters received gastric perfusion of 1 mL normal saline which was made by diluating astragalus polysaccharides at the dose of 1 g/kg） with 6 ones in each group. The experiment lasted 10 weeks. ②After ten weeks, levels of serum triacylglycerol, total cholesterol （TC）, low density lipoprotein cholesterol （C-LDL）, high density lipoprotein cholesterol （HDL-C） and glyeated serum protein （GSP） were measured with automatic biochemical analyzer. Level of serum insulin was assayed with radioimmunoassay （RIA）. Contents of type I and III myocardial collagen and immunohistochemical positive index （mean of gray scale × percentage in positive area） detected with avidin-blotin-peroxidase complex technology （ABC）. Levels of angiotensin Ⅱ in plasma and local cardiacmuscle were detected with RIA method.③Differences of measurement data were compared with t test. RESULTS： A total of 18 hamsters were involved in the analysis of rasults and 12 ones failed in modeling withdrew from the study. ④levels of blood glucose after modeling in the model group and andastragalus polysaccarides treatment group were significantly higher than that in the normal control group （P 〈 0.01）. At the 10^th week of experiment, level of blood glucose in the astragalus polysaccharides treatment group was obviously lower than that in the model group （P 〈 0.01）; Levels of serum