FEEDBACK CONTROL OF CHOLESTEROL SYNTHESIS IN MAN*

Abstract

The influence of dietary cholesterol on the synthesis of cholesterol by the liver was studied in liver biopsy samples from well-fed, unanesthetized human beings. Dietary cholesterol in amounts of 3 to 4 g/day suppressed almost completely the synthesis of cholesterol by the human liver. We conclude that, like all other animals so far examined, man possesses an hepatic feedback mechanism for regulating the synthesis of cholesterol. Also, the human liver appears to be capable of synthesizing cholesterol at rates similar to those of other animal species. Finally, the rates of hepatic cholesterol synthesis appear to be unrelated to the levels of plasma cholesterol.