Squalene in Human and Rat Blood Plasma*

Abstract

Radioactive squalene was observed transiently in human and rat plasma after the intravenous administration of Cl4-mevalonic acid. Identification of the labeled squalene included its chromatographic behavior and its formation of a thiourea adduct. Most of the labeled squalene was associated with the very low density (density <1.019) lipoprotein fraction, in which its concentration was estimated to be approximately 30 to 35 [mu]g/100 ml plasma in both species. The plasma squalene pool appears to be in close equilibrium with the larger liver squalene pool. Preliminary evidence was also obtained that suggests the presence of small amounts of lanosterol in plasma.