[The effect of progesterone on metabolism of cholesterol esters in macrophages cultured with acetylated low density lipoproteins].

Effect of progesterone on esterification of free cholesterol, on content of free cholesterol and its esters was studied in rat macrophages, cultivated in presence of acetyl-derivatives of low density lipoproteins (Ac-LDL), as well as on mobilization of cholesterol from macrophages. Progesterone at a dose of 0.5-10 micrograms per I ml of cultivating medium caused dose-dependent inhibition of I-14C-oleate incorporation into cholesterol esters of macrophages cultivated with Ac-LDL (50 micrograms of protein/ml). In the medium free of LDL progesterone caused an increase of cholesterol in macrophages by 45%, while addition of 100 micrograms/ml LDL led to a decrease of free cholesterol by 20% of the initial level. If macrophages pre-enriched with 4-C14-cholesterol were cultivated in LDL containing medium, progesterone increased the 4-14C-cholesterol liberation into medium and decreased the cholesterol content in macrophages. Under conditions of macrophages incubation in the LDL-free medium, progesterone increased the free cholesterol content in these cells but did not affect the 4-14C-cholesterol liberation into medium. The data obtained suggest that the progesterone-induced inhibition of free cholesterol esterification may increase its mobilization from macrophages only if the LDL acceptor function is unaltered.