Myocardial metabolism of plasma triglycerides in man

Arterial-coronary sinus differences of triglyceride concentration were determined in 11 healthy, resting fasting subjects by using an infusion of albumin-bound tritiated palmitate to produce endogenous labelling of plasma triglycerides and also by using a precise chemical method of triglyceride estimation in which glyceride glycerol is measured. A statistically significant arterial-coronary sinus difference in triglyceride radioactivity and chemical glyceride-glycerol was detected in 9 and 8 of the subjects, respectively. The overall mean value for these differences was statistically highly significant and was about 2% of the arterial level. The average myocardial triglyceride uptake calculated from either the isotope or chemical data would be about 20 μmol/l of plasma unless there is significant partial hydrolysis of circulating triglycerides or the myocardium does not take up the fatty acid released from triglycerides. Complete myocardial uptake and immediate oxidation of the fatty acid released would account for an average of 10 to 20% of the heart's energy supply in resting, fasting man.