Role of nitric oxide mechanisms in control of pyloric motility and transpyloric flow of liquids in conscious dogs

• Published in: Digestive diseases and sciences 1998-03, Vol.43 (3), p.506-512
• Main Authors: ANVARI, M, PATERSON, C. A, DANIEL, E. E
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Consciousness; Dogs; Enzyme Inhibitors - pharmacology; Food, Formulated; Fundamental and applied biological sciences. Psychology; Gastric Emptying - physiology; Gastrointestinal Motility - physiology; Manometry; Nitric Oxide - antagonists & inhibitors; Nitric Oxide - physiology; Nitric Oxide Synthase - antagonists & inhibitors; Nitroarginine - pharmacology; Pyloric Antrum - physiology; Pylorus - physiology; Stomach; Time Factors; Vertebrates: digestive system
• ISSN: 0163-2116; 1573-2568
• DOI: 10.1023/A:1018898621465

The role of nitric oxide (NO) mechanisms in control of pyloric function and transpyloric flow were investigated in six conscious dogs. Antropyloroduodenal motility, transpyloric flow, and gastric emptying were measured 15 min after intravenous injection of 100 ml of either saline, L-arginine (50 mg/kg), L-NNA (5 mg/kg), or L-arginine (50 mg/kg) followed by L-NNA (5 mg/kg). Infusion of L-NNA was associated with retardation of gastric emptying (65 +/- 6%) in the first 30 min, in comparison to the saline (90 +/- 3%) or L-arginine (90 +/- 2%). This effect was prevented by infusion of L-arginine prior to L-NNA, after which 89 +/- 3% of the liquid emptied in 30 min. There was a significant reduction (P < 0.05) in the number and volume of flow pulses, and an increase in pyloric tone (P < 0.05) after L-NNA in comparison to the other three test conditions. There were no differences, however, in the number of antropyloric or isolated pyloric pressure waves under the four conditions. Our findings suggest that NO mechanisms influence gastric emptying and transpyloric flow of nonnutrient liquids by altering the pyloric tone, thus increasing resistance to flow.