Upregulation of Escherichia coli heat-stable enterotoxin receptor in regenerating rat liver.

Academic Article

Abstract

  • Guanylate cyclase C (GC-C) is a transmembrane protein that serves as a receptor for the recently characterized endogenous ligand guanylin and for Escherichia coli heat-stable toxin (STa). Binding of either guanylin or STa to intestinal GC-C results in net chloride secretion. Although GC-C is expressed in the rat intestine throughout life, its expression in the rat liver has previously been shown to occur only during the perinatal period. As a step toward elucidating the role of this receptor in the liver, we tested the hypothesis that GC-C mRNA expression could be induced in the adult rat liver following 1) partial hepatectomy, a stimulus for hepatocyte proliferation; 2) intraperitoneal carbon tetrachloride injection, a model of hepatocyte regeneration in the presence of inflammatory changes; and 3) subcutaneous turpentine injection, which generates an acute phase response without hepatocyte proliferation. We demonstrated expression of GC-C mRNA in the regenerating rat liver following either partial hepatectomy or CCl4-induced hepatic necrosis. We have also shown that GC-C mRNA expression occurred in association with an acute phase reaction. Coordinate with the expression of GC-C mRNA, there was upregulation of radiolabeled STa binding to liver plasma membranes prepared from turpentine-treated rats. Maximal expression of GC-C occurred in preparations enriched for the canalicular domain. Although the function of GC-C in the liver is unknown, localization to the canalicular domain would be consistent with a role for GC-C in hepatic chloride secretion, especially in the perinatal liver and during hepatocyte regeneration.
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    Keywords

  • Animals, Bacterial Toxins, Blotting, Southern, Carbon Tetrachloride Poisoning, Cell Division, Cell Membrane, DNA Probes, Enterotoxins, Escherichia coli, Escherichia coli Proteins, Gastrointestinal Hormones, Gene Expression, Guanylate Cyclase, Hepatectomy, Ileum, Kinetics, Liver, Liver Regeneration, Male, Natriuretic Peptides, Oligonucleotide Probes, Peptides, Polymerase Chain Reaction, RNA, Messenger, Rats, Rats, Sprague-Dawley, Receptors, Enterotoxin, Receptors, Guanylate Cyclase-Coupled, Receptors, Peptide, Time Factors, Turpentine, Up-Regulation
  • Digital Object Identifier (doi)

    Author List

  • Laney DW; Bezerra JA; Kosiba JL; Degen SJ; Cohen MB
  • Start Page

  • G899
  • End Page

  • G906
  • Volume

  • 266
  • Issue

  • 5 Pt 1