Delayed gastric emptying induced by inhibitors of nitric oxide synthase in rats

Abstract

The effect of the nitric oxide (NO) synthase inhibitor, N G - nitro- l-arginine methyl ester, on gastric emptying of a non-nutrient solution was investigated in conscious rats. N G-Monomethyl- l-arginine (10 mg/kg i.v.) and N G - nitro- l-arginine methyl ester (3 or 10 mg/kg i.v.) inhibited the 20-min rate of gastric emptying of liquids by 34%, 69% and 84% respectively, whereas the 0.3 mg/kg of N G - nitro- l-arginine methyl ester or 3 mg/kg of N G - monomethyl- l-arginine had no effect. The inhibitory effect of N G - nitro- l-arginine methyl ester (3 mg/kg) was prevented by l-arginine (300 mg/kg i.v.), but not by d-arginine (300 mg/kg i.v.). N G - Nitro- l-arginine methyl ester (0.3–10 mg/kg) induced a dose-related increase in mean blood pressure up to 161 ± 10 mm Hg. Spontaneous hypertensive rats with a mean blood pressure of 180 ± 5 mm Hg had a gastric emptying rate of 51.9 ± 6.1%. These data indicate that NO synthase inhibitors given i.v. at doses that inhibit NO synthase, delay gastric emptying through mechanisms which are unrelated to changes in arterial blood pressure.