The Serum High Density Lipoproteins of Macacus rhesus

The serum high density lipoproteins, HDL2 (d 1.063 to 1.125 g per ml) and HDL3 (d 1.125 to 1.21 g per ml), of normal Macacus rhesus kept on a low fat diet were isolated by ultracentrifugal flotation and their properties compared with those previously reported on human products. Both monkey and human lipoproteins proved very similar, in terms of hydrodynamic, spectroscopic, immunological, and morphological criteria. However, the HDL2:HDL3 ratio in M. rhesus was 2:1, as compared to the 1:3 ratio in humans. Moreover, the sphingoymelin content of monkey HDL2 and HDL3 was significantly lower than that in man. Thus, the high density lipoproteins of M. rhesus are similar, but not identical, to those in man.