The incorporation and distribution of 3H oleic acid in the isolated perfused guinea-pig heart: a biochemical and EM autoradiographic study.

The incorporation of 3H oleic acid into tissue lipids of guinea pig heart was studied after 15, 30, 60 or 120 sec perfusion using EM autoradiography with 'hypothetical grain' analysis and lipid analysis by thin-layer chromatography. Radioactivity in triacylglycerol and phospholipid increased and in free fatty acid decreased with time. This corresponded to an increase in radioactivity associated with lipid droplets in the autoradiographs. High levels of radioactivity were found associated with the mitochondria after only 15 sec. The movement of fatty acids is interpreted in terms of transport mechanisms, concentration gradients and bound and unbound molecules.