GENETIC-DIFFERENCES OF LIPID-METABOLISM IN MACROPHAGES FROM C57BL 6J AND C3H/HEN MICE/

Cholesterol metabolism in macrophages from atherosclerosis-prone C57BL /6J mice was compared with that in macrophages from atherosclerosis-re sistant C3H/HeN mice. Plasma total cholesterol levels of both types of mice were significantly increased, but HDL cholesterol level was incr eased only in C3H/HeN mice when a high-cholesterol diet (1% cholestero l) was fed for 5 weeks. After incubation of macrophages from male and female mice on the high-cholesterol diet with beta-VLDL for 24 hours, cholesterol content in macrophages from C57BL/6J was approximately 1.5 - to 2.0-fold higher than in those from C3H/HeN mice. [H-3]Cholesterol oleate-beta-VLDL incorporation into macrophages from C57BL/6J mice on the high-cholesterol diet was greater than incorporation into those f rom C3H/HeN mice. The release of [3H]cholesterol from macrophages from C57BL/6J mice on the high-cholesterol diet was one seventh that from macrophages from C57BL/6J mice on the basal diet or that from macropha ges from C3H/HeN mice on the basal or high-cholesterol diet. Acid chol esterol esterase activity was almost the same in macrophages from any group. Acyl CoA:cholesterol acyltrans ferase activity in macrophages f rom C57BL/6J mice on the high-cholesterol diet increased compared with that from macrophages from C57BL/6J mice on the normal diet. Neutral cholesterol esterase activity in macrophages from C57BL/6J mice was ab out half of that in macrophages from C3H/HeN mice independent of the t ype of diet. There were no sex differences in these metabolisms. Consi dered with our previous data, these results suggested that a high-chol esterol diet may cause metabolic changes to accumulate cholesterol est er in macrophages from C57BL/6J mice in accordance with genetic abnorm alities.