Tonic regulation of mouse ileal ion transport by nitric oxide

RK Rao, PJ Riviere, X Pascaud, JL Junien and F Porreca

Department of Pharmacology, University of Arizona, College of Medicine, Tucson.

The possible role of nitric oxide (NO) in the regulation of intestinal ion transport was studied in isolated sheets of mouse ileum mounted in Ussing flux chambers. The competitive NO-synthase inhibitors NG-methyl- L-arginine (L-NMA), and NG-nitro-L-arginine (L-NNA) and the effects of NO released from acidified sodium nitrite solution were evaluated in tissues pretreated with guanethidine and atropine. Serosal L-NMA or L- NNA (10-300 microM), but not NG-methyl-D-arginine (D-NMA), produced a sustained concentration-related increase in short-circuit current (Isc) and potential difference (PD) with maximal Isc increases of 50.8 +/- 8.2 and 45.5 +/- 5.8 microAmps/cm2, respectively; mucosal application of L-NMA or L-NNA produced transient increases in Isc. The A50 (and 95% CL) values for serosal L-NMA and L-NNA were 25.6 (15.7-41.9) and 8.7 (5.1-14.9) microM, respectively. L-Arginine (0.1-10 mM), but not D- arginine, produced both a concentration-related reversal of L-NMA or L- NNA-induced increases in Isc. Additionally, pretreatment with L- arginine blocked the L-NMA or L-NNA effects, suggesting a competitive interaction. L-NMA-mediated increases in Isc were unaffected by bicarbonate-free buffer, whereas replacement of chloride ions with gluconate ions almost completely attenuated the response to L-NMA. Further, the effects of L-NMA or L-NNA were blocked by tetrodotoxin or chlorisondamine, suggesting neural actions involving ganglionic transmission.(ABSTRACT TRUNCATED AT 250 WORDS)

Volume 269, Issue 2, pp. 626-631, 05/01/1994
Copyright © 1994 by American Society for Pharmacology and Experimental Therapeutics

This article has been cited by other articles:

				S. Coon, R. Kekuda, P. Saha, J. R. Talukder, and U. Sundaram Constitutive nitric oxide differentially regulates Na-H and Na-glucose cotransport in intestinal epithelial cells Am J Physiol Gastrointest Liver Physiol, June 1, 2008; 294(6): G1369 - G1375. [Abstract] [Full Text] [PDF]

				F H MOURAD, J L TURVILL, and M J G FARTHING Role of nitric oxide in intestinal water and electrolyte transport Gut, February 1, 1999; 44(2): 143 - 147. [Full Text] [PDF]

				J L Turvill, F H Mourad, and M J G Farthing Proabsorptive and prosecretory roles for nitric oxide in cholera toxin induced secretion Gut, January 1, 1999; 44(1): 33 - 39. [Abstract] [Full Text] [PDF]

				R. Aizman, H. Brismar, and G. Celsi Nitric oxide inhibits potassium transport in the rat distal colon Am J Physiol Gastrointest Liver Physiol, January 1, 1999; 276(1): G146 - G154. [Abstract] [Full Text] [PDF]