Hydroxyproline concentration in the cardiac tissue was measured with the modified alkaline hydrolysis method. Values are expressed as the means ± standard error of the measurements. For all statistical comparisons, n=8–11 animals. P<0.05, AAC/AAC + EN/AAC + H2S vs. normal; P<0.05, AAC/AAC + EN/AAC + H2S vs. sham; P<0.05, AAC + EN/AAC + H2S vs. AAC. EN, enalapril.