Effects of losartan and captopril on reversing myocardial remodeling

Objective:To investigate the effects of losartan and captopril on reversing myocardial remodeling.Methods:Twenty-four Wistar rats were randomly divided into four groups-sham group,Infarcted group,losartan group, captopril group. c-fos mRNA expression was tested by reverse transcription and polymerase chain reaction(RT-PCR). Expression changes of cardiac collagen subtype Ⅰ, Ⅲ, fibronectin(FN) proteins were studied with immunohistochemistry and image analysis.Results:c-fos mRNA expression was enhanced on the 21st day after myocardial infarction ,and expressions of collagen Ⅰ, collagen Ⅲ and FN formation in infarcted group were significant(P 0.05 and P 0.01) on the 21st day compared with those in sham group respectively. In losartan group and captopril group, c-fos mRNA expression was inhibited ,and cardiac collagenⅠ, collagen Ⅲ, FN expressions were remarkably decreased (P 0.05 or P 0.01) compared with those in infarcted group, respectively.Conclusion:Losartan and captopril can downregulate c-fos mRNA expression, inhibite cardiac collagenⅠ, collagen Ⅲ, FN formation, and reverse myocardial remodeling after myocardial infarction. Effect of AT 1 receptor blocker on reversing myocardial remodeling is similar to that of angiotensin-converting enzyme inhitor.The results indicate that angiotensin-converting enzyme inhitor and AT 1 receptor blocker can substitute for each other.