PT  - JOURNAL ARTICLE
AU  - J. A. Schriefer
AU  - E. P. Broudy
AU  - A. H. Hassen
TI  - Inhibitors of Bradykinin-Inactivating Enzymes Decrease Myocardial Ischemia/Reperfusion Injury following 3 and 7 Days of Reperfusion
DP  - 2001 Sep 01
TA  - Journal of Pharmacology and Experimental Therapeutics
PG  - 970--975
VI  - 298
IP  - 3
4099  - http://jpet.aspetjournals.org/content/298/3/970.short
4100  - http://jpet.aspetjournals.org/content/298/3/970.full
SO  - J Pharmacol Exp Ther2001 Sep 01; 298
AB  - Inhibitors of bradykinin (BK)-inactivating enzymes protect from myocardial ischemia/reperfusion injury after short periods of reperfusion. However, protection after 2 to 3 h of reperfusion does not mean that myocardium remains viable for an extended time. Therefore, we examined the effects of inhibitors of angiotensin-converting enzyme (ramiprilat), EP24.11 (cFP-F-pAB), and EP24.15 (cFP-AAF-pAB) in a chronic model of myocardial ischemia/reperfusion injury. A left descending coronary artery was occluded for 30 min in anesthetized rabbits. Saline, ramiprilat, or endopeptidase inhibitors were given after 27 min of occlusion. The BK2 receptor antagonist HOE140 was administered in certain experiments. After ischemia, the occlusion was released, and the animal allowed to recover for 3 or 7 days. Surgery was then repeated, and the heart removed for determination of infarct size. In separate experiments, the heart was removed after 2 h of reperfusion for determination of BK tissue levels. Ramiprilat and endopeptidase inhibitors reduced infarct size at 3 and 7 days. Combining inhibitors further reduced infarct size after 3 days. The protective effect of the endopeptidase inhibitors was blocked by HOE140. Infarct sizes at 7 days were larger than at 3 days. The additive effect of multiple inhibitors was absent at 7 days. Ramiprilat and cFP-F-pAB significantly increased tissue BK levels. We conclude that inhibition of BK-inactivating enzymes protects endogenous BK from degradation and provides long-lasting protection from myocardial ischemia/reperfusion injury. A single treatment at the time of reperfusion does not prevent extension of the infarction between 3 and 7 days. The American Society for Pharmacology and Experimental Therapeutics