Effects of ACE inhibitor on the expression of GluT4 mRNA and protein in diabetic rat heart / 中国药理学通报

ABSTRACT

AIM To study effects of ACE inhibitor on the ex pression of GluT4 mRNA and protein in diabetic rat heart. METHODS The following groups of rats were randomly designed control rats, diabetic ra ts and diabetic rats treated with benazepril (an ACE inhibitor). After 4 weeks o f treatment, ACE activities were determined by fluorimetric assay in plasma and heart; Myocardial GluT4 mRNA expression were measured by Northern blot analysis; GluT4 protein expression were measured by Western blot analysis. RESULT S After 4 weeks of treatment, there was a significant increase in myocard ial ACE activities despite a trend toward reduce in plasma activitics, ACE activ ities were inhibited by 92 1%, 89 0% in plasma and heart, respectively; Northe rn blot analysis revealed that the expression of GluT4 mRNA was reduced in diabe tic rat heart by 40%, and treatment with benazepril did not prevent the diabetes -induced reduction of GluT4 mRNA; However, Western blot analysis revealed that benazepril did prevent the diabetes-induced reduction of GluT4 protein in cell membrane of diabetic rat heart. CONCLUSION Benazepril could significantly suppress ACE activities in diabetic rat heart, bu t it did not influence the expression of the myocardial GluT4 mRNA. However, it did prevent the diabetes-induced reduction of GluT4 protein in cell membrane of rat heart.