Coronary vasodilator properties of purine and pyrimidine derivatives.

The vasodilator potency of the adenine nucleotides has been quantitated. Adenosine and AMP were found to be of equal potency and approximately one fourth as effective as ADP and ATP in increasing coronary blood flow. With the exception of UTP, which was also one fourth as potent as ATP, the derivatives of the hypoxanthine, guanine, cytosine and unveil bases lacked vasodilator properties. An increase in myocardial oxygen consumption was observed during infusion of ATP and UTP. However, the elevation in coronary blood flow was greater than that necessary to meet the increased oxygen requirements of the myocardium.