Parameter Sham MI Sham + PRAZ MI + PRAZ Sarcoplasmic reticulum activity:         Ca2+-uptake (nmol Ca2+/mg/min) 56.1 ± 2.10 16.8 ± 1.45* 50.2 ± 2.43 23.5 ± 1.12# Ca2+-release (nmol Ca2+/mg/15 sec) 8.8 ± 0.45 4.0 ± 0.61* ± 0.36 4.4 ± 0.52 Myofibrillar ATPase activity         Mg2+-ATPase (μmol Pi/mg/hr) 3.3 ± 0.11 3.5 ± 0.13 3.2 ± 0.15 3.6 ± 0.13 Ca2+-stimulated ATPase (μmol Pi/mg/hr) 12.8 ± 0.55 8.0 ± 0.50* 80 ± 4.9 8.5 ± 0.61 Values are mean SE of 7 animals in each group. MI–Myocardial Infarction; PRAZ–Prazosin (10 mg/kg/day); *P<0.05 compared with the 20 week sham group; #P<0.05 compared with the 20 week MI group

Table 4: SR Ca2+-transport and MF ATPase activities in sham and infarcted animals with and without prazosin treatment for 8 weeks starting at 12 weeks after coronary artery occlusion.