T. Miki et al., DO ANGIOTENSIN-CONVERTING ENZYME-INHIBITORS LIMIT MYOCARDIAL INFARCT SIZE, Clinical and experimental pharmacology and physiology, 20(6), 1993, pp. 429-434
1. Effects of captopril, ramiprilat and Hoe 140, a specific bradykinin
receptor antagonist, on infarct size were assessed in a rabbit model
of myocardial infarction. 2. Rabbits were untreated or pretreated with
0.5 mg/kg of captopril, 0.05 mg/kg of ramiprilat or 20 nmol/kg of Hoe
140 before 30 min coronary artery occlusion and 72 h reperfusion. 3.
Captopril and ramiprilat treatment reduced systemic blood pressure by
about 10 mmHg without alteration of heart rate, and the dose of Hoe 14
0 almost completely blocked hypotensive response to intravenous inject
ion of bradykinin (100 ng/kg). 4. Infarct size expressed as percentage
of area at risk was 44.5+/-3.3% in the control group, 41.9+/-1.6% in
the captopril group, 51.8+/-2.7% in the ramiprilat group and 46.7+/-2.
2% in the Hoe 140 group. All percentages were not significantly differ
ent. 5. These data suggest that angiotensin converting enzymes (ACE),
with or without sulfhydryl groups do not limit myocardial infarct size
and that endogenous bradykinin in ischaemic myocardium does not play
a major protective role against ischaemic myocardial necrosis.