title: Endogenous nitric oxide in gastric alkaline response in the rat stomach after damage.
abstract: OBJECTIVE
  The gastric mucosa responds to hypertonic NaCl by significantly decreasing acid secretion. This study examined the role of nitric oxide in this phenomenon.
  
  
  METHODS
  A rat stomach was mounted in an ex vivo chamber and perfused with saline; then the potential difference (PD), pH, and acid and/or alkaline responses were measured before and after the application of 1 mol/L NaCl with or without pretreatment with NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of NO biosynthesis.
  
  
  RESULTS
  A dose of 1 mol/L NaCl caused a reduction in PD, a decrease in basal and histamine-stimulated acid secretion, and an increase in luminal HCO3-. Prior administration of L-NAME did not affect either the PD or the HCO3- response but significantly attenuated the inhibitory effect of 1 mol/L NaCl on acid secretion. This effect of L-NAME was antagonized by the simultaneous administration with L-arginine but not D-arginine. Histamine-stimulated acid secretion in the normal stomach was significantly reduced by the exogenous NO donor nitroprusside but not by L-NAME.
  
  
  CONCLUSIONS
  NO is involved in the mechanism of the gastric alkaline response after damage with 1 mol/L NaCl. Irritation of the gastric mucosa by hypertonic NaCl may release endogenous NO, which in turn inhibits acid secretion and unmasks luminal alkalinization caused by HCO3- flux in the damaged portion.
authors.affiliation: Department of Applied Pharmacology, Kyoto Pharmaceutical University, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Takeuchi
authors.forename: T
authors.initials: T
authors.lastname: Ohuchi
authors.forename: S
authors.initials: S
authors.lastname: Okabe
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D001639:Bicarbonates / Q000378:metabolism; D005744:Gastric Acid / Q000378:metabolism; D005745:Gastric Acidity Determination; D005753:Gastric Mucosa / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D006863:Hydrogen-Ion Concentration; D008297:Male; D008564:Membrane Potentials; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000502:physiology*; D009599:Nitroprusside / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012462:Saline Solution, Hypertonic
chemical_list: D001639:Bicarbonates; D012462:Saline Solution, Hypertonic; D009599:Nitroprusside; D009569:Nitric Oxide; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester