Journal of Lipid Research, Vol 31, 633-643, Copyright © 1990 by Lipid Research, Inc.
Rhesus monkey model of familial hypercholesterolemia: relation between plasma Lp[a] levels, apo[a] isoforms, and LDL-receptor function
L Neven, A Khalil, D Pfaffinger, GM Fless, E Jackson and AM Scanu
Department of Medicine, University of Chicago, IL 60637.
We previously described a family of rhesus monkeys in which three out of
six members had a spontaneous hypercholesterolemia related to a decrease in
number of low density lipoprotein receptors (LDL-R) (Scanu et al. 1988. J.
Lipid Res. 29: 1671-1681). During the current work an additional female
normocholesterolemic offspring was generated from the mating of the
original dam and sire. Moreover, from the breeding of one of the affected
male offspring with six unrelated normocholesterolemic female monkeys,
eight offspring were generated of which three were hypercholesterolemic on
a cholesterol-free diet and exhibited the same degree of LDL-R deficiency
as shown by studies in skin fibroblast cultures. All of the animals studied
had levels of plasma lipoprotein[a] protein ranging between 1.0 mg/dl and
57.5 mg/dl that were only weakly correlated with total plasma cholesterol,
LDL cholesterol, and apoB. LDL-R deficiency correlated with plasma LDL but
not Lp[a]. A 7 week fat challenge (16.5% lard, 0.64% cholesterol) that
raised the plasma LDL levels markedly had no effect on plasma Lp[a].
Animals with the single band apo[a] phenotype moving on SDS-PAGE faster
than apoB-100 exhibited a tendency for high plasma Lp[a] levels which,
however, varied widely. Wide variations in Lp[a] levels were also noted
with the other apo[a] phenotypes. Taken together our results demonstrate a
successful transmission to second generation animals of the LDL-R
deficiency phenotype and provide evidence that this phenotype correlates
well with plasma LDL levels but not Lp[a]. Our data also suggest that the
apo[a] gene is only partially involved in the regulation of the plasma
Lp[a] levels.