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

✍ Scribed by María Casadevall; Julián Panés; Josep M. Piqué; Norma Marroni; Jaume Bosch; Brendan J. R. Whittle

• Publisher: John Wiley and Sons
• Year: 1993
• Tongue: English
• Weight: 857 KB
• Volume: 18
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.1840180323

✦ Synopsis

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 mgkg, intravenously) caused a significant and dosedependent reduction in gastric mucosal blood flow in portal-hypertensive rats but had no effect on shamoperated 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 mgkg) 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 Aow produced by the higher dose of L-NAME. In portal-hypertensive rats the significant dose-dependent reduction in gastric muaosal blood flow induced by L-NAME (3 and 13 m e g ) was not significantly altered by pretreatment with indomethacin. Portal pressure was higher in portal-hypertensive than in sham-operated rats, and no significant differences were observed in this parameter between portal-hy-