Estimation of HDL cholesteryl ester kinetic parameters in the cebus monkey, an animal species with high plasma cholesteryl ester transfer activity

Abstract

We studied the kinetic parameters of high density lipoprotein (HDL) cholesteryl esters in the cebus monkey, an animal species with high plasma cholesteryl ester transfer activity. HDL were radiolabeled with cholesteryl [1- 14C]oleate and intravenously administered to 4 cebus monkeys. The calculated fractional catabolic rate (FCR) of the HDL cholesteryl esters was 0.081 ± 0.002 (mean ± SD) h −1 and the calculated residence time was 12.3 ± 0.3 h. The production or disposal rate of plasma HDL cholesteryl esters was 34.3 ± 4.5 μmol/h. The radiolabeled cholesteryl esters were rapidly transferred from the HDL to the very low and low density lipoproteins (VLDL + LDL) and the amount of tracer in the VLDL + LDL had already reached a maximum at 3.5 ± 0.7 h after tracer administration. The estimated fraction of VLDL + LDL cholesteryl esters derived from the HDL was 0.77 ± 0.06. We also used radiolabeled [1,2- 3H(N))cholesteryl palmityl ether to trace HDL cholesteryl esters, but the ether tracer was more slowly cleared from the plasma and less readily transferred between plasma lipoproteins than the ester tracer.