RESUMO
Objective:To investigate the effect of chronic alcohol consumption on both left ventricular myocardial collagen and diastolic function in rats,and their relationship thereof.Methods:Twenty-four male Wistar rats were randomly divided into 2 groups:control group(n=12)and ethanol group(n=12).The changes in cardiac diastolic function were evaluated by echocardiography and tissue Doppler imaging(TDI).The value of myocardial hydroxyproline content was determined by hydroxyproline reagent kit.The expressions of collagen Ⅰ and collagen Ⅲ mRNA were detected by RT-PCR analysis.Results:It was found that mitral E and mitral annulus Ea were decreased,mitral annulus Aa was increased,and isovolumic relaxation time(IVRT)was prolonged in the ethanol group compared with those in control group(P<0.05).The value of Ea/Aa ratio was greater than 1 in control group and less than 1 in ethanol group(P<0.01).It was found that myocardial hydroxyproline content,collagen Ⅰ,collagen Ⅲ mRNA expression and their ratio significantly increased in ethanol group compared with those in the control group(P<0.01).There was positive correlation between hydroxyproline content,collagen Ⅰ,collagen Ⅲ mRNA expression,and collagen Ⅰ /collagen Ⅲ mRNA ratio with IVRT(P<0.05),and negative correlation between hydroxyproline content,collagen Ⅰ,collagen Ⅲ mRNA expression,and collagen Ⅰ /collagen Ⅲ mRNA ratio with the Ea/Aa ratio(P<0.01).Conclusion:Chronic ethanol consumption can induce increase in left ventricular myocardial collagen synthesis and impairment in diastolic function in rats.Left ventricular diastolic dysfunction correlates with increase in myocardial collagen synthesis positively.