Objective: To observe the effects of nitric oxide (NO) and prostaglandin on gastric mucosal perfusion in rats with portal hypertensive gastropathy (PHG).
Methods: Two weeks after partial portal vein ligation, gastric mucosal blood flow (GMBF) was measured with the neutral red clearance method and the changes of portal venous pressure (PVP) were observed.
Results: GMBF and PVP were significantly higher in rats with PHG than in sham operated rats (P<0.01). Low dose inhibitor of NO synthesis N(-nitro-L-arginine methyl ester (L-NAME 1mg/kg, 4mg/kg) caused a significant and dose dependent reduction in GMBF in PHG rats, but had no effect on sham operated rats. High dose L-NAME (12 mg/kg) significantly decreased GMBF in both PHG and sham operated rats. The inhibition of prostaglandin synthesis with indomethacin significantly decreased GMBF in rats with PHG, but had no effect in sham operated rats. In sham operated rats pretreated with indomethacin, GMBF was not modified after and before injection of low dose L-NAME (4mg/kg); likewise, high dose of L-NAME (12mg/kg) did not alter the significant reduction in GMBF as compared with pretreatment without indomethacin. In PHG rats the significant dose dependent reduction in GMBF induced by L-NAME (4mg/kg, 12mg/kg) was not significantly different between pretreatment with and without indomethacin.
Conclusions: NO and prostaglandins play an important role in the regulation of GMBF in rats with PHG, but no synergistic interactions between them.