Saturation kinetics of palmitate uptake in perfused skeletal muscle.

We investigated the kinetics of palmitate uptake in a physiological skeletal muscle preparation by using the isolated perfused rat hindquarter. When plotted against the unbound plasma palmitate concentration, palmitate uptake displayed a simple Michaelis-Menten relation with a calculated Vmax and Km of 16.3 nmol.min-1.g-1 and 0.06 mumol.l-1, respectively. These results show that, as in isolated cell systems, uptake of free fatty acids in perfused skeletal muscle follows saturation kinetics consistent with carrier-mediated membrane transport of free fatty acids.