Urocortin protects coronary endothelial function during ischemia-reperfusion: a brief communication.
Urocortin is a vasodilator peptide related to corticotrophin-releasing factor, which may protect myocardium during coronary ischemia-reperfusion. To study whether urocortin also protects coronary endothelial function during ischemia-reperfusion, hearts from Sprague-Dawley rats were perfused at constant flow and then exposed to 15 mins ischemia followed by 15 mins reperfusion. In one series of experiments, we found that the coronary relaxation to urocortin (10(-11) to 10(-8) M) was reduced by ischemia-reperfusion (51 +/- 4% vs. 79 +/- 4% of the active tone, for the 10(-10) Mdose). In other series of experiments, we observed that ischemia-reperfusion reduced the coronary relaxation to a test dose of acetylcholine (10(-6) M) (25 +/- 2% vs. 54 +/- 9% of active tone), without modifying the relaxation to sodium nitroprusside (10(-6) M). Treatment with a low threshold concentration of urocortin (10(-11) M), administered before ischemia and during reperfusion, partly improved the coronary relaxation to acetylcholine (36 +/- 3% of active tone). These results suggest that ischemia-reperfusion impairs the coronary vasodilation to urocortin and produces endothelial dysfunction and that this endothelial dysfunction may be improved by urocortin.
García-Villalón
Angel Luis
AL
Departamento de Fisiología, Facultad de Medicina, Universidad Autónoma, 28029 Madrid, Spain. angeluis.villalon@uam.es
Sanz
Elena
E
Monge
Luis
L
Fernández
Nuria
N
Climent
Belén
B
Diéguez
Godofredo
G
D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid / Q000037:antagonists & inhibitors; D000109:Acetylcholine / Q000494:pharmacology; D000818:Animals; D002316:Cardiotonic Agents / Q000494:pharmacology*; D003331:Coronary Vessels / Q000187:drug effects*; D003346:Corticotropin-Releasing Hormone / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000187:drug effects* / Q000502:physiology; D008297:Male; D017202:Myocardial Ischemia / Q000503:physiopathology; D015425:Myocardial Reperfusion / Q000379:methods*; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D054832:Urocortins
D002316:Cardiotonic Agents; D054832:Urocortins; D009599:Nitroprusside; D019796:15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5,13-dienoic Acid; D003346:Corticotropin-Releasing Hormone; D000109:Acetylcholine