Coronary circulation in experimental traumatic shock, and effect of some vasoactive agents on its parameters

On 35 heparinized cats with experimental traumatic shock induced according to Cannon, changes in the coronary blood flow, produced by intravenous injections of noradrenaline, angiotensin, hydrocortisone, histamine, and serotonin, were studied. Traumatic shock was characterized by decreases in the coronary blood flow and organic oxygen uptake, despite a simultaneous decrease in the regional vascular resistance. Injections of noradrenaline (14-18 mug/kg) and angiotensin (29 mug/kg) induced, both in the initial normal state and in shock, increases in the coronary blood flow rate and in the regional oxygen uptake; an injection of hydrocortisone (7.1 mg/ml) produced similar effects in the normal state, but did not elevate the oxygen uptake in shock; an injection of histamine (32 mug/kg) had no effect on the coronary blood flow rate, but reduced the regional oxygen uptake both in the normal state and in shock; an injection of serotonin (30 mug/kg) exerted no major effects on the blood flow. The results obtained might serve as guidelines for pharmacological regulation of coronary circulation in shock.