Journal of Lipid Research, Vol 31, 965-973, Copyright © 1990 by Lipid Research, Inc.
Impaired plasma cholesteryl ester transfer with accumulation of larger high density lipoproteins in some families of baboons (Papio sp.)
RS Kushwaha, DL Rainwater, MC Williams, GS Getz and HC McGill Jr
Department of Physiology, Southwest Foundation for Biomedical Research, San Antonio, TX 78228.
Baboons from some families have a higher concentration of plasma high
density lipoproteins (HDL) on a chow diet and accumulate large HDL (HDL1)
when challenged with a high cholesterol and high saturated fat (HCHF) diet.
HDL1 from high HDL1 animals contained more (1.5-fold) cholesteryl ester
than HDL (HDL2 + HDL3) from high or low HDL1 animals. HDL from high HDL1
baboons had lower triglyceride content than that from low HDL1 baboons.
HDL3 or HDL labeled with [3H]cholesteryl linoleate was incubated with
entire lipoprotein fraction (d less than 1.21 g/ml) or very low density
lipoprotein + low density lipoprotein (VLDL + LDL) (d less than 1.045 g/ml)
and with lipoprotein-deficient serum (LPDS), and the radioactive
cholesteryl ester and mass floating at d 1.045 g/ml (VLDL + LDL) after the
incubation was measured. The transfer of cholesteryl esters from either HDL
or HDL3, prepared from plasma of high HDL1 animals fed chow or the HCHF
diet, was slower than the transfer from either HDL or HDL3 of low HDL1
animals, regardless of the source of transfer activity or the ratio of
LDL:HDL-protein used in the assay. Addition of HDL from high HDL1 baboons
into an assay mixture of plasma components from low HDL1 baboons decreased
the transfer of cholesteryl ester radioactivity and mass from HDL to VLDL
and LDL. In addition to HDL, a fraction of intermediate density lipoprotein
(IDL) and denser HDL were also effective in inhibiting the transfer. These
observations suggest that accumulation of HDL1 in high HDL1 baboons fed an
HCHF diet is associated with a slower transfer of cholesteryl esters from
HDL to LDL.(ABSTRACT TRUNCATED AT 250 WORDS)