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 V max and K m of 16.3 nmol · min −1 · g −1 and 0.06 μmol·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.