Journal article

Publication year: 2011

Pages: G207-G216

Journal: American Journal of Physiology - Gastrointestinal and Liver Physiology

Volume number: 300

Issue number: 2

ISSN: 0193-1857

eISSN: 1522-1547

DOI Link: https://doi.org/10.1152/ajpgi.00407.2010

Publisher: American Physiological Society

Abstract: 
Steidle J, Diener M. Effects of carbon monoxide on ion transport across rat distal colon. Am J Physiol Gastrointest Liver Physiol 300: G207-G216, 2011. First published November 18, 2010; doi:10.1152/ajpgi.00407.2010.-The aim of the present study was to investigate whether carbon monoxide (CO) induces changes in ion transport across the distal colon of rats and to study the mechanisms involved. In Ussing chamber experiments, tricarbonyldichlororuthenium( II) dimer (CORM-2), a CO donor, evoked a concentration-dependent increase in short-circuit current (I-sc). A maximal response was achieved at a concentration of 2.5 . 10(-4) mol/l. Repeated application of CORM-2 resulted in a pronounced desensitization of the tissue. Anion substitution experiments suggest that a secretion of Cl- and HCO3- underlie the CORM-2-induced current. Glibenclamide, a blocker of the apical cystic fibrosis transmembrane regulator channel, inhibited the I-sc induced by the CO donor. Similarly, bumetanide, a blocker of the basolateral Na+-K+-2Cl(-) cotransporter, combined with 4-acetamido-4'-isothiocyanato-stilbene-2,2'-disulfonic acid sodium salt, an inhibitor of the basolateral Cl-/HCO3- exchanger, inhibited the CORM-2-induced I-sc. Membrane permeabilization experiments indicated an activation of basolateral K+ and apical Cl- channels by CORM-2. A partial inhibition by the neurotoxin, tetrodotoxin, suggests the involvement of secretomotor neurons in this response. In imaging experiments at fura-2-loaded colonic crypts, CORM-2 induced an increase of the cytosolic Ca2+ concentration. This increase depended on the influx of extracellular Ca2+, but not on the release of Ca2+ from intracellular stores. Both enzymes for CO production, heme oxygenase I and II, are expressed in the colon as observed immunohistochemically and by RT-PCR. Consequently, endogenous CO might be a physiological modulator of colonic ion transport.

Harvard Citation style: Steidle, J. and Diener, M. (2011) Effects of carbon monoxide on ion transport across rat distal colon, American Journal of Physiology - Gastrointestinal and Liver Physiology, 300(2), pp. G207-G216. https://doi.org/10.1152/ajpgi.00407.2010

APA Citation style: Steidle, J., & Diener, M. (2011). Effects of carbon monoxide on ion transport across rat distal colon. American Journal of Physiology - Gastrointestinal and Liver Physiology. 300(2), G207-G216. https://doi.org/10.1152/ajpgi.00407.2010