Myocardial and Hepatocellular Fatty Acid Uptake

Fatty acid influx into human myocardium was studied in 15 patients during the cooling phase of cardiopulmonary bypass at myocardial temperatures of 370 to 25°C. The fitting of the data to a functional relation, developed in this study, revealed fatty acid influx to be a temperature-dependent saturable process corresponding to a Michaelis-Menten constant (K.) at 370C of 0.26±0.084 ,umol/g, a maximal fatty acid influx velocity (Vm.) at 37°C of 0.28±0.045 gumol/g per minute, activation energy for fatty acid binding to the putative carrier (E) of 23.8±5.6 kcal/mol, and a free energy for conformational change of the carrier (U) of 10.9±8.0 kcal/mol. In short-term cultured hepatocytes, K. increased in the absence of Na+ from