Delayed exercise-induced protection against arrhythmias in dogs--effect of celecoxib.

A 20-min period of treadmill exercise in dogs, sufficient to increase heart rate by 90-100 beats min(-1), markedly decreases the severity of the life-threatening ventricular arrhythmias that result when, following anaesthesia 24 h later, the left coronary artery is occluded. This protection was unaffected by the administration of the selective cyclooxygenase-2 inhibitor celecoxib (two times 3 mg kg(-1) given intravenously). These results show that prostacyclin, derived from cyclooxygenase-2, plays no role in this pronounced delayed cardioprotection.