OBSERVATIONS CONCERNING THE PRODUCTION AND EXCRETION OF CHOLESTEROL IN MAMMALS. XVI. THE RELATIONSHIP OF THE LIVER TO THE CONTENT AND CONTROL OF PLASMA CHOLESTEROL ESTER 1

Abstract

The rate of replacement of experimentally reduced plasma ester cholesterol content was studied in 7 rats whose plasma cholesterol level was reduced by plasmapheresis following which the stomach, small and large intestines, the pancreas and the spleen were removed. The average plasma cholesterol ester content was reduced from 38 to 9 mg/100 cc by the plasmapheresis; 12 hours later it had risen to 33 mg/100 cc, a rise equal to that in 10 control rats also plasmapheresed but not subjected to operation. Similar results were obtained when both kidneys were removed from 6 rats. However, when 60 to 70% of the liver was removed from 8 rats the loss of plasma ester cholesterol consequent upon plasmapheresis was not restored, even when free cholesterol was supplied by intravenous injection to provide substrate for the production of the ester. When excess ester cholesterol was supplied by intravenous injection to 10 controls, 5 eviscerated rats, and 5 eviscerated-hepatectomized rats, only the latter group proved unable to remove the ester cholesterol from the blood. Apparently liver serves as the chief organ both for the supply and withdrawal of plasma cholesterol ester.