Lisinopril has a cardio-protective effect on experimental acute autoimmune myocarditis in rats

Abstract

The present study investigated the effect of lisinopril on experimental autoimmune myocarditis (EAM) in rats, a histologically similar model to human acute myocarditis. Animals and methods. Twenty four, six week-old male Wistar rats were randomly allocated into 4 groups of 6 rats each. Group I received no treatment. Group II received lisinopril at a dose of 15 mg/kg/day suspended in 1 ml of 2% gum acacia daily, from day 1 to day 21. To induce myocarditis, animals of groups III and IV were injected by 1 mg of porcine cardiac myosin on days 1 and 8. In addition, animals of group IV received lisinopril in gum acacia daily, from day 1 to day 21. All rats were sacrificed on day 21. Serum levels of creatine phosphokinase, troponin-T, tumor necrosis factor-α and interleukin-6 were estimated. Hearts were processed for histopathological, as well as immunohistochemical study for thioredoxin (TRX) immunoreactivity. Results. The wall of hearts from rats of myocarditislisinopril group showed mild focal myocarditis and a significant decrease of the mean percentage of pyknotic nuclei in cardiomyocytes, coincident with a significant decrease in serum biomarkers levels and TRX immunoreactivity, compared to myocarditis group. Conclusion. The present study suggested a cardioprotective effect of lisinopril on acute EAM in rats, probably through a mechanism related to its suppressive effect on angiotensin II formation.