BODY CHOLESTEROL METABOLISM IN MAN. I. THE EQUILIBRATION OF SERUM AND TISSUE CHOLESTEROL*†

Abstract
The rate of equilibration of serum and tissue cholesterol has been studied in 9 human patients who died 1 to 226 days after receiving C14-labeled cholesterol. The cholesterol in all tissues excepting brain and blood vessels attained complete equilibration with serum cholesterol within 1 month. The brain cholesterol showed only negligible degrees of equilibration with serum cholesterol throughout the study. Complete equilibration of normal arterial intimal cholesterol with serum cholesterol was observed after prolonged periods, indicating that the cholesterol in normal vessels is in a dynamic state of equilibrium with serum cholesterol. Significant Cl4-radioactivity was present in atherosclerotic plaques although the presence of atherosclerosis appeared to retard the rate at which equilibration with serum cholesterol occurred.