Angiotensin converting enzyme inhibitors and angiotensin II receptor antagonists in experimental myocarditis

Myocarditis is a disease whose pathogenesis is not completely understood and whose prevalence is likely underestimated. Individuals afflicted with this condition may be treated with agents that relieve symptoms arising from inflammation and concurrent cellular damage. One class of drugs commonly used in the treatment of myocarditis includes the angiotensin converting enzyme inhibitors, such as captopril, enalapril and lisinopril, and the angiotensin Pi receptor antagonists, such as L-158,809 and losartan. The effects of these drugs on cardiomyopathy have been studied using a variety of animal models of heart failure and hypertension. However, less research has been done in the area of animal models of frank myocarditis. Here we review the use of angiotensin converting enzyme inhibitors and angiotensin Pi receptor antagonists in animal models of myocarditis. We extend the implications of that published work by correlation with results from studies of other disease models and in vitro experiments that highlight the immunomodulatory potential of these compounds. The literature strongly suggests that aggressive therapy employing angiotensin converting enzyme inhibition and/or blockade of angiotensin Pi receptors is beneficial. Treatment is useful not only for reducing complications associated with myocarditis, but also for downregulating the potential autoimmune component of disease without increasing the levels of the infectious agent that may initiate the myocarditis.