[Reactions of high-density lipoproteins and their subfractions with the intimas of atherosclerotic human aortas].

A ratio of cholesterol esters to free cholesterol was decreased in the total fraction of high density lipoproteins (LPHD) after incubation of the fraction with human aorta intima impaired by atherosclerosis. The same alterations occurred in the reaction of aorta intima with the fraction LPHD3. During incubation of the intima with LPHD2 less distinct decrease was observed in the ratio of cholesterol esters to free cholesterol. The decrease in the ratio of cholesterol fractions, found both in total LPHD and LPHD3, was caused by transfer of free cholesterol from intima cells to LPHD. Thus, LPHD (namely LPHD3 fraction) were able to accept free cholesterol from aorta intima cells; this mechanism is apparently responsible for protective effect of LPHD in atherogenesis.