Abstract
Incorporation of mevalonic acid into cholesterol by rat liver homogenates is favored by (a) use of tissue from very young rats, (b) use of a "loose" homog-enizer, and (c) saturation of the homogenate with straight O2 and stoppering. Incorporation of mevalonic acid is less in the presence of compounds that may be intermediates or antimetabolites of cholesterol biosynthesis. With whole homogenates biosynthesis is not markedly influenced by the method of killing the rats or by additions of ATP.