Reflex vagal inhibition of gastric motility by intestinal nociceptive stimulation in the cat.

The effect on gastric motility of various irritative stimuli to the small and large intestine and peritoneum were studied in anesthetized cats. Mechanical stimulation of the jejunum or colon elicited gastric relaxation, which was not blocked by antiadrenergic or anticholinergic drugs but was abolished by vagotomy. Long-lasting gastric relaxation with similar characteristics was observed on jejunal surgery, spontaneous peritonitis, or chemical irritation of the abdominal cavity with acid or methanol. Diathermic lesions of the gut caused less gastric inhibition than mechanical and chemical stimuli. Afferent electric stimulation of jejunal and colonic nerves induced gastric relaxation with similar characteristics as mechanical stimulation in the same regions. It is concluded that mechanical and chemical irritation of the gut and intestinal surgery and peritonitis are accompanied by a gastric relaxation due to activation of the vagal nonadrenergic inhibitory fibers to the stomach. This vagal mechanism is suggested to be important for the suppression of gastric motility in paralytic ileus.