Stimulation of myocardial lactate extraction by oxfenicine (L-hydroxyphenylglycine).

Abstract

In animal experiments oxfenicine (L-hydroxyphenylglycine) (LHPG) has been shown to increase myocardial carbohydrate utilization and decrease fat consumption. Seven patients, six of whom proved to have coronary artery disease, were studied during diagnostic cardiac catheterization. Myocardial substrate extraction, coronary sinus flow, cardiac output and left ventricular pressure were measured at basal heart rale and three pacing rates before and after 800 mg oxfenicine (LHPG). A small decrease in systolic pressure at low heart rates and reduction of end-diastolic pressure at the highest pacing rate were the only haemodynamic changes observed after the drug. Coronary sinus flow and myocardial oxygen uptake did not change, although there was a small fall in arterio-venous oxygen difference at basal heart rate. After the drug lactale extraction ratio increased in all patients at each heart rate. Pyruvate extraction ratio increased after oxfenicine (LHPG) significantly at basal heart rate and the lowest pacing rate. Arterial free fatty acid concentration rose and extraction ratio fell. It is concluded that oxfenicine (LHPG) has a potent effect upon lactate metabolism and is without major haemodynamic effects.