Lipid Turnover in an Isolated Population of Irradiated Bone Marrow Cells

Abstract

In vitro experiments are reported in this paper for the incorporation of ${\rm K}\text{-palmitate-}1\text{-}{\rm C}^{14}$ into triglycerides, diglycerides, phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl serine, lysolecithin, and sphingomyelin. At intervals of 1 day or more after total-body irradiation, there was a significant inhibition of the esterification of fatty acids into phospholipids, primarily lecithin. Labeled diglycerides did not increase under these conditions. The labeling of triglycerides in the irradiated marrow continued at essentially the same rate as in the control for the first 2 days after 800 R, after which it, too, was inhibited by ionizing irradiation. We conclude that enzymatic pathways for triglyceride biosynthesis are more resistant to damage by irradiation than are the pathways for the biosynthesis of phosphatides.