THE EFFECT OF NITRIC-OXIDE SYNTHASE BLOCKADE AND INDOMETHACIN ON GASTRIC-EMPTYING AND GASTRIC CONTRACTILITY

The aim of the present study was to investigate the effect of nitric o xide (NO) synthase inhibition on gastric emptying rate in conscious ra ts and on gastric muscle contractility. The involvement of NO was also investigated in indometacin-induced (25 mg/kg, s.c.) changes in gastr ic emptying rate and smooth muscle contractility. L-NAME (N-G-nitro-L- arginine methyl ester; 10 mg/kg, i.v.) inhibited the gastric emptying rate compared to controls and this effect was abolished by L-arginine (300 mg/kg, i.v.). Similarly, indometacin treatment led to a significa nt delay of gastric emptying rate with respect to vehicle-treated rats . Gastric longitudinal and circular muscle strips of L-NAME or indomet acin-treated rats showed a reduction in contractile responses to carba chol. The results demonstrate that NO synthase blockade and indometaci n treatment delay gastric emptying in conscious rats, concomitant with reduced responsiveness to carbachol, in vitro.