AJP - Gastrointestinal and Liver Physiology, Vol 267, Issue 5 836-G842, Copyright © 1994 by American Physiological Society

ARTICLES

Effect of fasting on the enterohepatic circulation of bile acids in rats

R. Dumaswala, D. Berkowitz, K. D. Setchell and J. E. Heubi
Division of Pediatric Gastroenterology, Children's Hospital Research Foundation, Cincinnati, Ohio 45229.

Fasting Sprague-Dawley rats for 72 h resulted in inhibition of bile salt synthesis, reduced bile flow and bile salt secretion rate, and reduced duodenal and portal venous bile acid concentrations. The initial rate of ileal brush border membrane (BBM) taurocholate (TC) uptake was markedly reduced in the fasted group (45% of control). TC uptake by BBM was saturable, with similar maximal transport velocity for the fasted rats and controls (1.69 +/- 0.06 and 1.62 +/- 0.017 nmol.mg protein-1.min-1, respectively) but higher Michaelis-Menten constant for fasted rats than for controls (96.9 +/- 20.0 and 54.9 +/- 10.2 microM, respectively). Hepatic basolateral membrane (BLM) TC uptake was enhanced by 65% in fasted animals. Transport kinetics in BLM had a similar Michaelis-Menten constant for fasted rats and controls (31.6 +/- 8.2 and 27.3 +/- 4.7 microM, respectively), and maximal transport velocity was higher for fasted rats than for controls (1.84 +/- 0.017 and 1.11 +/- 0.014 nmol.mg protein-1.min-1). The cholesterol-to-phospholipid ratio and fluorescence anisotropy in BLM of fasted rats decreased, and the cholesterol-to-phospholipid ratio and fluorescence anisotropy increased in ileal BBM. Alterations in the enterohepatic circulation of bile acids with fasting may alter expression of transport proteins for bile salts by direct effects on synthesis or indirectly through membrane lipid compositional changes.

This article has been cited by other articles:

				C. G. Dietrich, I. V. Martin, A. C. Porn, S. Voigt, C. Gartung, C. Trautwein, and A. Geier Fasting induces basolateral uptake transporters of the SLC family in the liver via HNF4{alpha} and PGC1{alpha} Am J Physiol Gastrointest Liver Physiol, September 1, 2007; 293(3): G585 - G590. [Abstract] [Full Text] [PDF]

				X. Gui and R. E. Carraway Involvement of mast cells in basal and neurotensin-induced intestinal absorption of taurocholate in rats Am J Physiol Gastrointest Liver Physiol, August 1, 2004; 287(2): G408 - G416. [Abstract] [Full Text] [PDF]

				X. Gui, P. R. Dobner, and R. E. Carraway Endogenous neurotensin facilitates enterohepatic bile acid circulation by enhancing intestinal uptake in rats Am J Physiol Gastrointest Liver Physiol, December 1, 2001; 281(6): G1413 - G1422. [Abstract] [Full Text] [PDF]

				F. R. Simon, J. Fortune, M. Iwahashi, S. Bowman, A. Wolkoff, and E. Sutherland Characterization of the mechanisms involved in the gender differences in hepatic taurocholate uptake Am J Physiol Gastrointest Liver Physiol, February 1, 1999; 276(2): G556 - G565. [Abstract] [Full Text] [PDF]