ESTERIFICATION OF ¹⁴C‐LABELLED CHOLESTEROL BY RETICULO‐ENDOTHELIAL CELLS

Abstract

14C-labelled cholesterol injected intraperitoneally into rats was shown to be taken up by the reticulo-endothelial cells of the sternal lymph nodes and partly converted into 14C-labelled cholesteryl ester. The specific activity of the 14C_ labelled cholesterol in the nodes fell rapidly, while that of the 14C-labelled cholesteryl ester formed remained relatively high, suggesting that esterification of the cholesterol and its fixation as cholesteryl ester was brought about by reticulo-endothelial cells. It was also shown that 14C-labelled cholesterol was taken up by rabbit macrophages in vitro and partly esterified in these cells. The significance of the findings in relation to the pathogenesis of atheroma is discussed.

Fatty Acid Patterns of Cholesterol Esters Synthesized by Reticulo‐endothelial Cells

“…CHOLESTEROL suspensions taken up by reticulo-endothelial cells in rat lymph nodes or by rabbit macrophages in vitro, are partially converted to cholesterol ester [Day and French, 1959;Day and Gould-Hurst, 1961]. The fatty acid pattern of cholesterol esters may also influence their subsequent metabolism [Klein and Martin, 1959;Lewis et at., 1961] and much interest has arisen concerning fatty acid patterns of cholesterol esters in various situations, particularly in the arterial wall in atherosclerosis [Sinclair, 1956;Bottcher et al, 1960].…”

A COMPARISON OF THE OXIDATION OF CHOLESTEROL‐26‐14C, PALMITATE‐1‐14C AND TRIPALMITIN‐1‐14C BY MACROPHAGES IN VITRO

“…'4C-LABELLED cholesterol taken up by reticulo-endothelial cells is readily converted to 14C-labelled cholesteryl ester and evidence has been obtained that such esterification may fix the cholesterol in these cells [Day and Gould-Hurst, 1961]. It has also been shown that the uptake of cholesterol by reticulo-endothelial cells is followed by the accumulation, either by synthesis or deposition, of phospholipid and esterified fatty acids in the cells [Day, 1960 a].…”