梓醇对2型糖尿病大鼠心肌纤维化及心肌细胞形态学的影响

Effects of Catalpol on Myocardial Fibrosis and Myocardial Cells Morphology in Rats with Type 2 Diabetes Mellitus

目的:探讨梓醇对2型糖尿病(type 2 diabetes mellitus,T2DM)大鼠心肌纤维化及形态学的影响。方法:采用随机数字表法将90只SPF级雄性Wistar大鼠随机分为正常组10只和实验组80只。实验组大鼠高脂高糖饲料喂养8周后,腹腔注射链脲佐菌素(streptozotocin,STZ)溶液15 mg/kg制备T2DM模型。将成模大鼠根据空腹血糖(fasting plasma glucose,FPG)、体质量随机分为模型组、二甲双胍组与梓醇低、中、高剂量组。二甲双胍组灌胃二甲双胍混悬液90 mg/kg,梓醇低、中、高剂量组分别灌胃梓醇2.5、5、10 mg/kg,正常组和模型组灌胃等体积生理盐水,每日1次,均灌胃12周。末次给药后,测定各组大鼠FPG;免疫组化法检测心肌组织转化生长因子β_(1)(transforming growth factor-β_(1),TGF-β_(1))表达;HE染色观察心肌组织结构情况。结果:与模型组比较,梓醇高、中、低剂量组大鼠FPG及心肌TGF-β_(1)降低(P<0.05);梓醇高剂量组与正常组比较,心肌纤维、胞质、胶原纤维、细胞核均无显著差异。模型组与梓醇低剂量组心肌纤维排列紊乱或不规整,部分溶解、断裂,甚至呈小片状分布,胞质染色不均匀,中度或轻度肿胀;部分细胞核变形,固缩,甚至碎裂消失;心肌间隙显著增宽,可见大量或少量炎性细胞或成纤维细胞。二甲双胍组与梓醇中剂量组心肌纤维排列略规整,心肌细胞核极少部分变形;心肌间隙略增宽,炎性细胞较少。结论:梓醇可降低T2DM大鼠FPG与心肌纤维化水平,可能为保护T2DM大鼠心肌细胞的有效手段。

Objective:To study the effects of catalpol on myocardial fibrosis and morphology in the rats with type 2 diabetes mellitus(T2DM).Methods:SPF grade healthy male Wistar rats were randomized into 10 ones in the normal group and 80 ones in the experiment group using random number table method.The rats in the experimental group accepted peritoneal injection of STZ solution,15 mg/kg,to prepare T2DM models after feeding with high-fat and high-sugar fodder for eight weeks.Rat models were divided into the model group,melbine(DMBG)group,low,moderate and high dose groups of catalpol according to FPG and body mass.DMBG group was drenched with DMBG suspension,90 mg/kg,low,moderate and high dose groups of catalpol accepted intragastric administration of catalopl at 2.5,5 and 10 mg/kg respectively,the normal group and the model group accepted equivalent volume of physiological saline by gavage,once each day,drenched for 12 weeks.Since the last dose,to detect FPG,immunohistochemical method was applied to detect the expressions of TGF-β_(1) in myocardial tissue;HE staining to observe the morphology of myocardial cells.Results:Compared with the model group,the levels of FPG and myocardial TGF-β_(1) reduced in high,moderate and low dose groups of catalpol(P<0.05);there was no significant difference in myocardial fiber,cytoplasm,collagen fibers and nucleus when high dose group was compared with the normal group.The myocardial fibers were disordered or irregular,partly dissolved,broken,even distributed in small flakes,the cytoplasm was stained unevenly,with moderate or slight swelling.Some nuclei were deformed,showing pyknosis,even disintegrated in the model group and low dose group.The myocardial gap widened significantly,large or small numbers of inflammatory cells or fibroblasts could be seen.the arrangement of myocardial fibers was slightly regular,and the nucleus of myocardial cells was rarely deformed in DMBG group and moderate dose group;myocardial gap is slightly widened,with fewer inflammatory cells.Conclusion:Catalpol could reduce the levels of FPG and myocardial fibrosis in T2DM rats,and it may be an effective way of protecting myocardial cells in T2DM rats.