Lipoprotein lipid transport by livers from normal and CCl₄-poisoned animals

¹ Department of Pharmacology, School of Medicine, Vanderbilt University, Nashville, Tennessee; and Department of Biochemistry, School of Medicine, University of Florida, Gainesville, Florida

Triglyceride release by livers isolated from normal fed animals has been shown previously to be stimulated by the addition of palmitate to the perfusate. It may be concluded from the data reported herein that the output of cholesterol and phospholipid into the d < 1.006 lipoprotein class is proportional to release of triglyceride into this fraction. Triglyceride, cholesterol, and phospholipid may be secreted in constant proportion in order to maintain a physical-chemical stability and solubility of the very low density lipoprotein whose primary function is transport of triglyceride from liver to extrahepatic tissues. CCl₄, which inhibits triglyceride release by the liver, also inhibits output of cholesterol and phospholipid into the d < 1.006 lipoprotein. Release of cholesterol into the d < 1.063 lipoprotein is not clearly related to non-esterified fatty acid levels in the medium, to triglyceride release by the liver, or to other lipids present in this fraction. The serum lipoprotein class containing the largest initial concentration of any lipid is not necessarily identical with the fraction having the major net hepatic release of that lipid. Thus, each lipoprotein class released may have specific and different lipid carrier functions.

Key Words: hepatic lipid transport • perfused liver • triglyceride metabolism • lipid metabolism • fatty acid metabolism • fatty liver • rat liver • CCl₄ hepatotoxicity • cholesterol • phospholipids

Submitted on April 30, 1964

This article has been cited by other articles:

				R. W. Mahley, T. P. Bersot, V. S. Lequire, R. I. Levy, H. G. Windmueller, and W. V. Brown Identity of Very Low Density Lipoprotein Apoproteins of Plasma and Liver Golgi Apparatus Science, April 17, 1970; 168(3929): 380 - 382. [Abstract] [PDF]