[Changes in geometric parameters of liposomes and plasma lipoproteins during enrichment with cholesterol].

Geometrical parameters of liposomes and lipoproteins of human blood plasma with different content of cholesterol are determined by the methods of radiationless energy transfer between fluorescence probes and by spectroscopy of the optical shift. The bilayer thickness of liposomes containing 33% (mol.) cholesterol is 48 +/- 3A, that of liposomes of pure phosphatidyl choline--32 +/- 2 A. The surface area is equal to (0.41 +/- 0.02).10(3) m2/g of lipid and (0.47 +/- 0.01).10(3) m2/g of lipid, respectively. The radii of lipoproteins of very low density were 13.9 and 25.5 nm, those of the low density--10.0 and 9.5 nm and those of high density--5.3 and 7.8 nm by the data of radiationless energy transfer and optical mixing, respectively. In case of hyper cholesternemia these values are equal to 20.7 and 31.9 nm, 12.7 and 11.1 nm, 5.2 and 5.9 nm, respectively. The results obtained are compared with data of other methods.