PLASMA CHOLESTERYL ESTER SYNTHESIS, CHOLESTERYL ESTER TRANSFER PROTEIN-CONCENTRATION AND ACTIVITY IN HYPERCHOLESTEROLEMIC WOMEN - EFFECTS OF THE DEGREE OF SATURATION OF DIETARY FATTY-ACIDS IN THE FASTING AND POSTPRANDIAL STATES

Hypercholesterolemic women (n = 19) sequentially maintained on a long- term saturated (SAT) or a polyunsaturated (PUFA) fatty acid-rich diet, respectively, were studied in the fasting state and after a meal rich in SAT or PUFA. When apo B-containing lipoprotein was excluded from p lasma the in vitro HDL-C-14-cholesterol esterification rate was identi cal for the saturated (SAT) and polyunsaturated (PUFA) fatty acid diet s, and did not increase during the postprandial period. Rates of trans fer of C-14-cholesteryl ester to apo B-containing lipoproteins from HD L were also similar for both diets in the fasting state and increased to the same extent in the postprandial period in parallel with the ris e in plasma triglycerides. When transfer data were related to the plas ma concentration of apo B, the gain of cholesteryl ester by the trigly ceride-containing particles (VLDL + LDL) also increased in the postpra ndial period to a similar extent for both diets. Cholesteryl ester tra nsfer protein (CETP) concentration measured by radioimmunoassay was si milar during both experimental diets, although greater in the postpran dial period for the PUFA diet. The rate limiting factor for CETP-media ted transfer of HDL-derived cholesteryl ester (CE) was the plasma trig lyceride concentration, that is, the content of triglycerides per lipo protein particle and the quantity of TG-containing particles (VLDL + L DL). In contrast, the fatty acid composition of these particles had le ss effect on CETP-mediated CE transfer.