ISOTOPIC STUDIES OF PLASMA CHOLESTEROL OF ENDOGENOUS AND EXOGENOUS ORIGINS 1

Abstract

This study was undertaken in order to compare the metabolic behavior of plasma cholesterol de- rived from the diet with that of cholesterol syn- thesized in vAvo from acetate (1). Cholesterol labeled with either isotopic carbon or hydrogen was administered orally to human subjects and the incorporation into plasma cholesterol was fol- lowed over an extended period. In certain in- stances, both endogenous and exogenous choles- terol metabolism were studied simultaneously by the use of appropriately labeled acetate and cho- lesterol. These techniques were also applied to an examination of the behavior of plasma cholesterol in four patients with hypercholesterolemia. EXPERIMENTAL Subjeces. The patients were hospitalized in the James Ewing Hospital unit of Memorial Center; all were in good clinical condition and a summary of pertinent data appears in Table Of the seven patients reported, three had normal plasma cholesterol levels and four had hypercholesterolemia of varied etiology.