Effect of 2-phenylaminoadenosine (CV-1808) on ischemic ST-segment elevation in anesthetized dogs.

The effect of 2-phenylaminoadenosine (CV-1808) against myocardial ischemia was studied in anesthetized dogs. During intravenous infusion of CV-1808 (0.25 and 0.5 microgram/kg/min for 10 min) the ST-segment elevation in the epicardial ECG induced by a 5-min occlusion of a coronary arterial branch was occasionally enhanced in association with cardiac acceleration. In a dose of 0.5 microgram/kg/min, the agent inhibited the ST elevation 30 and 60 min after administration. The same dose did not change myocardial blood flow in the ischemic area despite significant systemic hypotension. In hearts with continuous coronary occlusion, CV-1808 (0.3 and 1.0 microgram/kg, i.v. bolus) increased the retrograde blood flow from the ischemic area immediately after administration, suggesting a collateral vasodilating action. Nifedipine (0.5 and 2.5 microgram/kg/min, i.v. for 10 min) and nitroglycerin (0.5 and 5.0 microgram/kg/min, i.v. for 10 min) had no influence on the ischemic ST-segment elevation, while a significant inhibition was seen with propranolol (0.5 mg/kg, i.v.). A moderate hypotension was induced by CV-1808, nifedipine, and nitroglycerin, while a significant reduction in cardiac function was seen after dosing with propranolol.