波动性高糖对乳鼠心肌细胞肥大的影响

Effects of Glucose flunctuation on Cardiomyocyte hypertrophy in neonatal rats

目的探讨波动性糖环境对体外培养的乳鼠心肌细胞肥大的影响。方法取出生后2天SD大鼠乳鼠心脏,采用胶原酶消化法获取心肌细胞,进行心肌细胞原代培养。常规培养心肌细胞72h,待细胞搏动良好,将其随机分为3组:①对照组:给予稳定的糖浓度(5.5mmol/L);②高糖组:给予稳定高糖浓度(25.5mmol/L);③波动性糖组:波动性糖浓度为5.5mmol/L和25.5mmol/L,每12h交替,其他培养条件保持一致。Bradford法检测各组细胞总蛋白质含量;计算机细胞图像分析系统测量单个细胞的体积;采用3H-亮氨酸掺入法,用液闪仪测定心肌细胞蛋白质合成速率。结果 1.高糖组和波动性糖组与对照组相比心肌细胞蛋白含量均增加,波动性糖组与高糖组相比二者增加的数值相近。2.高糖组和波动性糖组与对照组相比心肌细胞体积均有明显增加。3.高糖组与波动性糖组与对照组相比均有蛋白合成的增加。波动性糖组与高糖组相比没有显著性差异。结论波动性糖有促进心肌细胞肥大的作用,其作用强度与单纯性高糖相仿。在糖尿病心肌病中,波动性糖也是引起心肌细胞肥大、心肌顺应性下降的原因之一。提示临床治疗糖尿病患者时,除了要控制血糖防止血糖过高,而且还要保持血糖的稳定,减少血糖波动所导致的心肌损害。

Objective To identify the effects of glucose flunctuation on the hypertrophy of cultured neonatal rat ventricular myocytes.Methods 2-day-old Sprague-Dawley rats were killed,and their hearts were removed.and then digested with trypsin 72 hours after seeding,all the cells are well connected,and beating at the same pace.Then we divided them into 3 groups： the normal glucose control group was given a glucose concentration of 5.5mmol/L;the high-glucose group with 25.5mmol/L,and the fluntuation group was internatively given 5.5mmol/L and 25.5mmol/L glucose.The other conditions were kept the same.The protein content was assayed with Bradford method.The cardiomyocyte volume was measured by computer photograph analysis system.The protein synthesis was assayed with 3H leucine intake method.Results The total cellular protein content and cellular volume,cellular protein synthesis showed an increase in both high-glucose and flunctuated-glucose groups.and the degree of their increase was similar.Conclusion Not only the high glucose itself,but also the fluntuation glucose can induce hypertrophy of the cultured myocardial cells,and the level of their effects is quite similar.This suggests that,when treating diabet patients,especially those one with diabetic cadiomyopathy,we should pay more attention to the flunctuation of their blood glucose level.