高脂喂养联合STZ腹腔注射对MKR糖尿病鼠心肌损伤的观察

Observation of Myocardial Injury in MKR Diabetic Rats by High-fat Feeding Combined with STZ Intraperitoneal Injection

目的建立骨骼肌胰岛素样生长因子1及胰岛素双受体功能缺失(Mouse overexpressing a dominantnegative IGF-I receptor specifically in muscle,MKR)转基因小鼠糖尿病合并心肌损伤的模型,观察MKR鼠在糖尿病病程中的心肌损伤表现。方法2018年9月—2019年1月选取10只C57小鼠,设为正常组,普通饲料喂养;选取24只MKR鼠分为模型组、空白组,高脂饲料喂养,每组12只。模型组小鼠腹腔注射40mg/kg的链脲佐菌素(Streptozotocin,STZ,),正常组、空白组小鼠腹腔注射40mg/kg的柠檬酸盐缓冲液。记录各组小鼠一般情况、体质量及空腹血糖,检测TG、TC、LDL-C、HDL-C观察脂代谢情况,检测cTnI和CK-MB评估心肌损伤情况,光镜及电镜下观察心肌结构。结果第15周,模型组MKR鼠多食、多饮、多尿表现典型,体质量较第10周显著下降,差异有统计学意义(P<0.05)。模型组、空白组空腹血糖均≥11.1mmol/L,明显高于正常组小鼠,差异有统计学意义(P<0.05)。与空白组对比,模型组空腹血糖更高,差异有统计学意义(P<0.05)。与正常组比较,模型组TG、TC、LDL-C水平更高,HDL-C更低,差异有统计学意义(P<0.05)。与空白组相比,模型组MKR鼠cTnI、CK-MB水平更高,差异有统计学意义(P<0.05)。与空白组比较,模型组MKR鼠心肌组织在光镜及电镜下损伤程度更重。结论经高脂喂养联合STZ腹腔注射造模后的MKR鼠糖尿病特征典型,高糖、高脂显著,心肌损伤严重。

Objective To establish a model of skeletal muscle insulin-like growth factor 1 and insulin dual receptor deficiency(Mouse overexpressing a dominant-negative IGF-I receptor specifically in muscle,MKR)transgenic mice with diabetes mellitus combined with myocardial injury,and to observe the myocardial injury performance of MKR mice in the course of diabetes mellitus.Methods From September 2018 to January 2019,10 C57 mice were set up as normal group and fed with normal chow,while 24 MKR mice were divided into model group and blank group with 12mice in each groups,and fed with high fat chow.The mice in the model group were injected intraperitoneally with 40mg/kg streptozotocin(STZ),and the mice in the normal and blank groups were injected intraperitoneally with 40 mg/kg citrate buffer.The general condition,body weight and fasting blood glucose of each group were recorded,TG,TC,LDL-C and HDL-C were measured to observe the lipid metabolism,cTnI and CK-MB were measured to assess the myocardial injury,and the myocardial structure was observed under light and electron microscopy.Results At week 15,the model group MKR rats showed typical polyphagia,polyphagia and polyuria,and their body weight decreased significantly compared with week 10,and the difference was statistically significant(P<0.05).The fasting blood glucose in the model group and the blank group was≥11.1 mmol/L,which was significantly higher than that in the normal group,the difference was statistically significant(P<0.05).Compared with the blank group,the fasting blood glucose was higher in the model group,the difference was statistically significant(P<0.05).Compared with the normal group,TG,TC and LDL-C levels were higher and HDL-C was lower in the model group,the difference was statistically significant(P<0.05).Compared with the blank group,cTnI and CK-MB levels were higher in the model group MKR rats,the difference was statistically significant(P<0.05).Compared with the blank group,the myocardial tissue of MKR rats in the model group was more damaged under light and electron microscopy.Conclusion The diabetic characteristics of MKR rats after high-fat feeding combined with STZ intraperitoneal injection modeling were typical,with significant high glucose and high fat and severe myocardial injury.