[Self-regulation of the functional state of high density lipoproteins and its disorders in hypoalphacholesterolemia (review].

Cholesterol-acceptor and cholesterol-transport functions of high density lipoproteins appear to occur by means of the principle of selfregulation as these lipoproteins (particles) included a number of active units responsible for their biological function. These units were as follows: a) protein-lipid structure of surface monolayer of high density lipoprotein particles, which enables to intercalate the molecules of unesterified cholesterol, b) the enzymatic system, responsible for cholesterol esterification (lecithin-cholesterol acyltransferase--LCAT), involving the enzyme second substrate lecithin and activator apoprotein A-1, c) the system of nonenzymatic controlled transport of cholesterol esters, developed during the LCAT-reaction, involving the lipid-transport protein. On the basis of the hypothesis results, obtained in examination of persons with low and high level of high density lipoprotein cholesterol in blood plasma, were analyzed. Correlation between a decrease in cholesterol-acceptor and -transport functions of the lipoproteins and impairments in the system, responsible for selfregulation of their functional state, corroborated the hypothesis developed.