Density distribution, characterization, and comparative aspects of the major serum lipoproteins in the common marmoset (Callithrix jacchus), a new world primate with potential use in lipoprotein research

Abstract

Qualitative, quantitative, and comparative aspects of the serum lipoprotein profile in the Common marmoset (Callithrix jacchus), a New World primate, are described. Density gradient ultracentrifugation was used to evaluate lipoprotein distribution and to establish criteria for isolation of discrete molecular fractions. The major lipoprotein classes banded isopycnically on the gradient with the following hydrated densities: VLDL, d less than 1.017 g/mL; LDL, d = 1.027--1.055 g/mL; HDL fraction I, d = 1.070--1.127 g/mL; and HDL fraction II, d = 1.127--1.156 g/mL. Electrophoretic, immunological, and electron microscopic analyses attested to the purity of these fractions: the characteristics of each were assessed by chemical analysis, electron microscopy, immunological techniques, and polyacrylamide gel electrophoresis of their protein moieties. Marmoset VLDL and LDL were closely akin to those of man in size and chemical composition, although the former were richer in triglyceride; electrophoretic and immunological data showed the major protein component of VLDL and LDL to be a counterpart to human apo-B. The two HDL subfractions, i.e., HDL-I and HDL-II, corresponded in size and chemical composition to human HDL2 and HDL3, respectively, although slight differences in neutral lipid content were detected. By immunological and electrophoretic criteria, the major apolipoprotein of marmoset HDL was analogous to human apo-AI. In contrast, marked dissimilarities were evident in the complements of low molecular weight, tetramethylurea-soluble polypeptides of marmoset and human lipoproteins. Quantitatively, the human and marmoset lipoprotein profiles were not dissimilar, although HDL was the major class (approximately 50%); in fasting animals, serum concentrations of VLDL, LDL, and HDL were 50--90, 170--280, and 338--408 mg/dL, respectively. C. jacchus was distinct from man in displaying a greater proportion of its total HDL in the less dense (HDL-II) subfraction (marmoset HDL-I/HDL-II = approximately 4:1; human HDL2/HDL3 = approximately 1:3). These data indicate that, as an experimental animal for lipoprotein research, the Common marmoset combines the advantages of ready availability and maintenance with a serum lipoprotein profile which resembles, in many qualitative and quantitative aspects, that found in man.

Isolation and characterization of plasma lipoproteins of common marmoset monkey. Comparison of effects of control and atherogenic diets.

“…20 - 21 The values are also well within the range reported for both Old and New World monkeys. 636 The fasted plasma triglyceride concentrations (-87 mg/dl) were in good agreement with those recently reported for this species, 20 and within the range (62 to 108 mg/dl) found for six species of New World monkeys by Rudel and Lofland.…”

Lipoprotein(a) and apolipoprotein(a) in a New World monkey, the common marmoset (Callithrix jacchus). Association of variable plasma lipoprotein(a) levels with a single apolipoprotein(a) isoform.

“…Indeed, the invariant diameter of Lp(a) across the density interval from 1.048 to 1.076 g/ml distinguished it from LDL, which presented as one or more bands per subfraction and which decreased progressively in size (from a major component of 29 nm diameter at d=1.019 g/ml to one of 25.2 nm at d=1.060 g/ml) with an increase in density. Considerable overlap in the density distributions of LDL and HDL occurred in fraction 10 of d=1.055-1.065 g/ml, as reported earlier 15 and recently confirmed 18 ; in addition, Lp(a) was a component of this subfraction (Figure 2). …”

“…Marmoset Lp(a) and LDL isolated from the same plasma pool were distinguished by the elevated cholesteryl ester content and diminished proportions of both protein and phospholipid in the latter. As noted earlier, 15 marmoset and human LDLs were of similar chemical composition. Purified marmoset Lp(a) and LDL were also distinct in their electrophoretic mobility in agarose gel, with Lp(a) migrating to a pre-/3 position and LDL to a /3 position (data not shown).…”

“…14 Indeed, it was such characteristics that originally prompted us to propose this species as an appropriate and promising model for lipoprotein research, 15 in addition to our observation that both the qualitative and quantitative aspects of lipoprotein and apolipoprotein profile in C. jacchus closely resemble those found in normolipidemic humans. 1516 More recently, the susceptibility of the marmoset to dietinduced atherosclerosis, as originally described by Dreizen et al, 17 has been confirmed 18 and in addition has been extended to demonstrate the occurrence of both foam cell lesions and proliferative intimal plaques in monkeys hyperresponsive to diets supplemented with cholesterol and saturated fat.…”

Lipoproteins and heat shock proteins as measures of reproductive physiology in the soft shell clam, Mya arenaria

“…The plasma fraction was subjected to a modification of the standard lipoprotein density gradient centrifugation protocol (Redgrave et al, 1975;Chapman et al, 1979). Plasma density was adjusted to 1.25 g/mL by the addition of solid KBr.…”