Derangements in myocardial purine and pyrimidine nucleotide metabolism in patients with coronary artery disease and left ventricular hypertrophy.

Studies in animal models of myocardial ischemia and left ventricular hypertrophy have demonstrated a number of derangements in purine and pyrimidine nucleotide content of myocardium that are postulated to play a role in the pathogenesis of muscle dysfunction in these disorders. The present study examined myocardium of patients with coronary artery disease, left ventricular hypertrophy, or neither of these two abnormalities, to determine whether derangements in purine and pyrimidine nucleotide metabolism occur in humans. In patients with coronary artery disease, endocardial content of ATP, GTP, UTP, CTP, and creatine phosphate was reduced and ranged between 60% and 86% of the amount found in the epicardium. In patients without coronary artery disease or ventricular hypertrophy, endocardial content of these nucleotides was equal to or greater than that of epicardium. Endocardial and epicardial content of inosine was increased in patients with coronary artery disease, and after vein bypass grafting inosine content fell to the levels observed in myocardium of patients with normal coronary arteries. In patients with left ventricular hypertrophy, endocardial content of ATP, GTP, UTP, CTP, and creatine phosphate was also reduced and ranged between 64% and 88% of the epicardial content. In contrast to results obtained in patients without left ventricular hypertrophy, epicardial content of GTP, UTP, and CTP was increased by 131%, 123%, and 132% in hypertrophied myocardium. Thus the changes noted in myocardial nucleotide content in patients are similar to those noted in animal models of occlusive coronary disease and ventricular hypertrophy. These results suggest that the pathophysiological abnormalities in nucleotide metabolism noted in animal models also occur in human myocardium.