Journal article

Publication year: 1991

Pages: 225-230

Journal: Eicosanoids

Volume number: 4

Issue number: 4

ISSN: 0934-9820

Publisher: Springer

Abstract: 

The effect of carbocyclic thromboxane A2 (CTXA2) on short-circuit current (Isc) was studied in two preparations of the rat colon descendens, one with and one without the submucosal plexus. In both preparations, CTXA2(10(-7)-5 X 10(-6)mol.l-1)increased Isc concentration-dependently. Its action was not inhibited by the neurotoxin, tetrodotoxin, or by indomethacin, indicating a direct action on the epithelium. The increase in Isc was dependent on the presence of Cl- and HCO3--anions in the medium, but it was not affected by inhibitors of Cl- secretion such as furosemide or a Cl- channel blocker. Measurements of the unidirectional fluxes of Na+ and Cl- revealed that the dominant action of CTXA2 was an inhibition of the mucosa to serosa flux of Cl-. The action of CTXA2 was prevented by pretreatment with the thromboxane receptor blocker, SK&F 88046. It was also inhibited by TMB-8, a substance preventing the release of Ca2+ from intracellular stores, but its effect was not dependent on the presence of extracellular Ca2+. The results indicate that thromboxanes can modulate Cl- transport through the colonic epithelium by a mechanism dependent on intracellular Ca2+.

Harvard Citation style: Diener, M. and Rummel, W. (1991) Carbocyclic thromboxane A2 inhibits Cl- absorption in the rat colon, Eicosanoids, 4(4), pp. 225-230

APA Citation style: Diener, M., & Rummel, W. (1991). Carbocyclic thromboxane A2 inhibits Cl- absorption in the rat colon. Eicosanoids. 4(4), 225-230.