Journal of Lipid Research, Vol. 13, 32-38, January 1972
Copyright © 1972 by Lipid Research, Inc.

Fate of intravenously administered particulate and lipoprotein cholesterol in the rat

Åke Nilsson and D. B. Zilversmit

Graduate School of Nutrition, and Section of Biochemistry and Molecular Biology, Division of Biological Sciences, Cornell University, Ithaca, New York 14850

Unesterified radioactive cholesterol, both bound to serum lipoproteins and dispersed in ethanol-saline, was injected into bile fistula and intact rats. Due to phagocytosis, mainly by the liver macrophages, intravenously injected cholesterol in ethanol-saline disappears from the bloodstream significantly faster than lipoprotein-bound cholesterol.

Soon after the initial phagocytosis, the particulate isotopic cholesterol started to reappear in blood, reaching a maximal radioactivity in blood 10-24 hr after injection. Although the radioactive cholesterol reappears in serum in both esterified and unesterified form, it is likely that cholesterol is released from the phagocytic cells as unesterified cholesterol which is then esterified intravascularly or at other sites. In the bile fistula rats, somewhat more of the lipoprotein cholesterol than of the particulate cholesterol appeared in bile early after injection. However, cholesterol turnover calculated from a twopool model was the same for rats injected with lipoproteinbound or particulate cholesterol.

Supplementary key words cholesterol particles • serum lipoprotein • colloidal chromic phosphate • phagocytosis • cell isolation • liver macrophages • serum cholesterol • cholesteryl ester • bile acids • bile cholesterol

Submitted on May 14, 1971
Accepted on July 19, 1971

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				C. C. Schwartz, J. M. VandenBroek, and P. S. Cooper Lipoprotein cholesteryl ester production, transfer, and output in vivo in humans J. Lipid Res., September 1, 2004; 45(9): 1594 - 1607. [Abstract] [Full Text] [PDF]

				D. Q-H. Wang and M. C. Carey Measurement of intestinal cholesterol absorption by plasma and fecal dual-isotope ratio, mass balance, and lymph fistula methods in the mouse: an analysis of direct versus indirect methodologies J. Lipid Res., May 1, 2003; 44(5): 1042 - 1059. [Abstract] [Full Text] [PDF]

				E. Bravo, A. Cantafora, M. Avella, and K. M. Botham Metabolism of Chylomicron Cholesterol Is Delayed by Estrogen. An In Vivo Study in the Rat Experimental Biology and Medicine, February 1, 2001; 226(2): 112 - 118. [Abstract] [Full Text]