Effect of dopamine on the blood supply and oxygen balance of the ischemic myocardium

: In acute experiments on anesthetized cats the effect of dopamine administered in doses of 1, 5, 10 and 20 g/kg intravenously and 10 g/kg/min by intravenous drip was studied. The drug (10 g/kg and 10 g/kg/min) was found to cause a significant and prolonged increase of total coronary blood flow, a growth of oxygen consumption by the myocardium, a decrease of oxygen tension in the heart muscle against the background of poorly pronounced arterial hypertension during a simultaneous administration and tendency towards arterial hypotension. When administered in doses of 1 and 5 g/kg intravenously dopamine induced little positive shifts of the parameters under study, and in a dose of 20 g/kg intravenously decreased total coronary blood flow, oxygen consumption by the heart and increased oxygen tension in the myocardium against the background of moderate arterial hypertension.