Tissue distribution of 14C-labelled triolein in a soybean oil emulsion. An autoradiographic study in rat and mouse.

A fed and a starved group of mice were injected with a 14C-labelled triolein emulsion, similar to Intralipid, in a dose corresponding to 0.1 mg triglyceride per gram body weight. The animals were sacrificed from 30 sec to 24 h after injection. The tissue distribution of the fat emulsion depended on the nutritional state of the animals. A marked concentration of radioactivity was found in the gastric mucosa of all animals as soon as 30 sec after injection which declined with time but was still clearly discernible in the autoradiograms 24 h after injection. Although the radioactivity only demonstrates the presence of the labelled oleic acid without indication of the degree of triglyceride lipolysis, the autoradiograms showed marked differences in the concentration of radioactivity between the various groups of skeletal muscles and between the different parts of the reticulo-endothelial system.