Effects of cholesterol feeding on primate serum lipoproteins. III. The change in high density lipoprotein components.

Sooty mangabey (Cercocebus atys) monkeys had a lower serum HDL cholesterol concentration than any other Old World monkey species reported. In addition, they had a higher serum Lp(a) concentration than other species. The mangabeys were fed a cholesterol-fat diet for 5 weeks. HDL2 and HDL3 amounts were determined from the two peaks apparent upon analytical ultracentrifugation. In the first 1-3 weeks, 13 of the 14 mangabeys increased 30% (mean) in total HDL, this increase occurring only in the HDL2 fraction. After 5 weeks, HDL and HDL2 decreased markedly. During the cholesterol feeding, HDL3 continually decreased in flotation rate, indicating it was either smaller and/or denser. HDL2 and HDL3 separated well on molecular sieving agarose columns during the diet period, whereas a single symmetrical elution peak was found for chow-fed HDL. Thus on a cholesterol-fat diet, HDL2 and HDL3 increased in difference in molecular size.