American Journal of Clinical Nutrition, Vol 16, 88-96, Copyright © 1965 by The American Society for Clinical Nutrition, Inc.

The Effects of Choline on Hepatic Ultrastructural Changes Associated with the Intravenous Administration of Fat

¹ From the Pathology Division, U. S. Army Medical Research and Nutrition Laboratory, Fitzsimons General Hospital, Denver, Colorado, and the Department of Pathology, The Mount Sinai Hospital, New York, New York

The administration of intravenous fat emulsion to rats produces dilatation of the hepatic rough endoplasmic reticulum similar to that which occurs in choline deficiency. In the present study the changes occurring in the livers of rats receiving multiple injections of an intravenous fat emulsion while maintained on choline-deficient, choline-rich and stock diets were determined by light and electron microscopy. Severe fatty metamorphosis of the liver developed in all rats on choline-deficient diets. This fatty change was increased by intravenous injection of Intralipid. Dilatation of the hepatic rough endoplasmic reticulum was produced in rats on a stock diet given injections of Intralipid, as well as in rats on choline-deficient diets, rats on choline-deficient diets given injections of Intralipid and in rats on choline-rich diets given injections of Intralipid. Dilatation of the rough endoplasmic reticulum associated with the intravenous administration of Intralipid was not prevented by dietary supplementation with choline. This indicates that the mechanism by which Intralipid produces dilatation of the hepatic rough endoplasmic reticulum is more complex than simply the production of a relative choline deficiency.

A possible explanation for dilatation of the rough endoplasmic reticulum is presented on the hypothesis that rough endoplasmic reticulum undergoes morphologic and quantitative enzymatic change to become smooth endoplasmic reticulum. This is thought to be a compensatory phenomenon of the hepatocyte to metabolize the increased intracellular lipid.