Abstract
We studied the effects of the electrolyte composition (K, Ca, Na) and prostaglandin E1 of the extra-cellular fluid on the tension development of isolated canine coronary arterial strips. In 20mEq/l potassium solution, 4.7mEq/l calcium produced coronary artery contraction. This Ca-induced contraction was partially inhibited dose-dependently (between 10-15M and 10-12M) by prostaglandin E1. Above 10-11M, intensity of the inhibition did not change. In the presence of 20mEq/l potassium, the reduction of sodium concentration to 12mEq/l increased the tension of coronary artery. Prostaglandin E1 did not affect this tension development. After 5min perfusion of prostaglandin E1, Ca-induced contraction was not inhibited. It is concluded that low calcium, high sodium cardioplegic solution may relax the canine coronary artery. Addition of prostaglandin E1 to cardioplegic solution may reduce the coronary artery contraction partially.
