Abstract
The influence of adenosinetri-phosphate (ATP) on biosynthesis of cholesterol and precursors from mevalonic acid was studied with relatively crude (200 xg supernatant) and more refined (9000 xg supernatant) fractions of rat liver homogenate under aerobic and anaerobic conditions following preincubation with or without added ribonuclease. Mevalonic acid incorporation occurred under conditions favorable for oxidative phosphorylation or under conditions where the ATPase of tissue fragments had been removed by centrifugation (9000 xg). Ribonuclease inhibition of mevalonic acid utilization occurred only under O2 and in the presence of tissue fragments relatively rich in ATPase.