ENALAPRIL DOES NOT PREVENT THE MYOCARDIAL-ISCHEMIA CAUSED BY THE CHRONIC INHIBITION OF NITRIC-OXIDE SYNTHESIS

In rats, chronic administration of the nitric oxide (NO) inhibitor N-o mega-nitro-L-arginine methyl ester (L-NAME) causes arterial hypertensi on, cardiac hypertrophy and myocardial ischemic alterations such as ne crosis and fibrosis. In this study, we evaluated the effect of 8 weeks of treatment with enalapril maleate on cardiac weight and on the deve lopment of the histological alterations induced by L-NAME. Enalapril s ignificantly inhibited the development of both arterial hypertension ( 117.2 +/- 5.8, 161.8 +/- 8.8 and 122.0 +/- 10.6 mm Hg, for control, L- NAME- and L-NAME + enalapril-treated animals, respectively) and left v entricular hypertrophy (1.36 +/- 0.13, 1.60 +/- 0.04 and 1.48 +/- 0.05 mg/g, for control, L-NAME- and L-NAME + enalapril-treated animals, re spectively), but had no effect on the myocardial lesions. These findin gs demonstrate that although the renin-angiotensin system plays a majo r role in the development of arterial hypertension and cardiac hypertr ophy, it does not modulate the ischemia-induced myocardial alterations observed in this model.