【Objective】 To investigate the relationship between expression of miRNA1 and cadiomyocyte hypertrophy in diabetic rats in vivo and in vitro. 【Methods】 The cardiac function

ANP mRNA

BNP mRNA

and miRNA1 in the hearts of STZ induced diabetic rats 8 weeks after the establishment of model were observed respectively (nDCM = 15

nNC=10). Neonatal rat cardiomyocytes were isolated and cultured in 5 mmol/L glucose (normal glucose

NG) or 30 mmol/L glucose (high glucose

HG) for 24

48

and 72 hours. The expression of miRNA1 was examined on each time point

so as to the cellular diameters

protein level

ANP mRNA and BNP mRNA. The relationship between miRNA1 and hypertrophic effect caused by high glucose was analyzed.【Results】 After 8 weeks of diabetes

diabetic rats showed cardiac dysfunction

decrease of miRNA1 and increase of ANP and BNP mRNA. The expression of miRNA1 in HG group increased at first and decreased afterwards (F = 15.109

P = 0.001). The changes of cellular diameters and protein level in HG group were gradually increased with cultured time and significantly higher than those in NG group. The expressive tendency of ANP and BNP mRNAs in HG group were similar with the expression of miRNA1. Particularly

the expression of ANP mRNA positively correlated with the expression of miRNA1 (r = 0.990

P = 0.01). 【Conclusion】 High glucose induced the alteration of miRNA1 expression in neonatal rat cardiomyocytes and diabetic rats. This alteration of miRNA1 in neonatal rat cardiomyocytes was accompanied by increase of cardiomyocyte diameter and cellular protein level. The expression of ANP mRNA was related with the expression of miRNA1 positively.