Poor regression of myocardial hypertrophy following concomitant chronic alcohol ingestion and angiotensin converting enzyme (ACE) inhibition

In the following study we examined the combined effect of chronic alcohol a dministration and antihypertensive drug treatment in spontaneously hyperten sive rats (SHR). SHR were fed alcohol for six weeks while taking the angiot ensin converting enzyme (ACE) inhibitor lisinopril. After six weeks, protei n synthesis rates, contractile protein levels and protease activities were examined in control; alcohol; control+lisinopril; alcohol+lisinopril groups . Lisinopril treatment significantly reduced left ventricular mass, protein content and contractile proteins in control rats, but these effects were n ot as pronounced in alcohol+lisinopril rats. Protein synthesis rates in bot h mixed and myofibrillar fractions were not significantly different in any of the 4 groups. The enzyme activities of the proteases cathepsin D and dip eptidyl aminopepetidase I increased in control+lisinopril rats, however, th is effect was not evident in alcohol+lisinopril rats. Contractile proteins identified by one-dimensional electrophoresis showed that lisinopril treatm ent reduced all contractile proteins in control rats. However, in alcohol+l isinopril rats, myosin heavy chain was higher than in control+lisinopril ra ts. In summary, alcohol ingestion impairs the regression of the hypertrophi c myocardium in SHR on ACE-inhibitor treatment, which was reflected by alte red protein metabolism. This study suggests that successful antihypertensiv e treatment may not be achieved if alcohol misuse is evident. (C) 2000 Else vier Science Inc. All rights reserved.