Abstract
Aqueous extracts of mitochondria from livers of starved animals inhibited hepatic cholesterol synthesis. Some properties of a mitochondrial extract prepared from starved rabbits were studied. The extract depressed the incorporation of both 2-14c-acetate and 3H-mevalonate into cholesterol by rat liver homogenates, giving concentration-dependent responses. The active factor was unstable to heat, but stable under in vitro incubation conditions, to pH changes, and to storage in the dark and cold. It was cationic and associated with 1 or more large molecules (mol. wt. 50,000-150,000); it was not cleaved by trypsin digestion. Fractionation experiments did not result in any significant enrichment of inhibitory activity.