Involvement of nitric oxide and prostaglandins in gastric mucosal hyperemia of portal-hypertensive anesthetized rats

Hepatology. 1993 Sep;18(3):628-34.

Abstract

This study investigates the effects of inhibition of nitric oxide synthesis by NG-nitro-L-arginine methyl ester (L-NAME), the inhibition of prostaglandin synthesis with indomethacin and the combined effects on gastric mucosal hyperemia of ketamine-anesthetized rats with portal hypertension induced by partial portal vein ligation. The hydrogen gas-clearance technique was used for measurement of gastric mucosal blood flow. Blood pressure increased with L-NAME administration in a similar manner in portal-hypertensive and sham-operated rats. Low doses of L-NAME (1 and 3 mg/kg, intravenously) caused a significant and dose-dependent reduction in gastric mucosal blood flow in portal-hypertensive rats but had no effect on sham-operated animals. With a higher dose of L-NAME (13 mg/kg, intravenously), a significant decrease in gastric mucosal blood flow was observed in both portal-hypertensive and sham-operated rats. Indomethacin pretreatment (5 mg/kg, subcutaneously) caused a significant decrease in basal gastric mucosal blood flow of portal-hypertensive rats but did not modify this parameter in sham-operated animals. In sham-operated rats pretreated with indomethacin, the lower dose of L-NAME (3 mg/kg) did not significantly modify basal gastric mucosal blood flow. Likewise, pretreatment with indomethacin in sham-operated rats did not augment the significant reduction in gastric mucosal blood flow produced by the higher dose of L-NAME. In portal-hypertensive rats the significant dose-dependent reduction in gastric mucosal blood flow induced by L-NAME (3 and 13 mg/kg) was not significantly altered by pretreatment with indomethacin.(ABSTRACT TRUNCATED AT 250 WORDS)

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anesthesia, General
  • Animals
  • Arginine / analogs & derivatives*
  • Arginine / pharmacology
  • Blood Pressure / drug effects
  • Gastric Mucosa / blood supply*
  • Hypertension, Portal / metabolism
  • Hypertension, Portal / physiopathology*
  • Indomethacin / pharmacology*
  • Male
  • NG-Nitroarginine Methyl Ester
  • Nitric Oxide / metabolism*
  • Prostaglandins / metabolism*
  • Rats
  • Rats, Sprague-Dawley
  • Reference Values
  • Regional Blood Flow / drug effects

Substances

  • Prostaglandins
  • Nitric Oxide
  • Arginine
  • NG-Nitroarginine Methyl Ester
  • Indomethacin