[Lecithin-cholesterol acyltransferase activity and lipid composition of high density lipoprotein subfractions in hyperalphalipoproteinemia].

In blood plasma of men activity of lecithin-cholesterol acyl transferase /LCAT/ was elevated when the cholesterol concentration was increased in the fraction of high density lipoproteins /HDL/; the enzymatic activity was evaluated by the rate of 3H-cholesterol esterification in endogenous HDL. The phenomenon observed was accompanied by an increase in content of HDL2 subfraction: The content of free cholesterol was found to increase in the HDL2 fraction obtained from persons with hyper-alpha-lipoproteinemia. Analysis of the data obtained showed that LCAT activity was preferentially dependent on HDL3 cholesterol concentration in persons with low and middle content of HDL cholesterol, and--on HDL2 cholesterol concentration in patients with hyper-alpha-lipoproteinemia.