Spinovagal reflex modulation of gastric motility in response to mucosal nociceptive stimulation in the anaesthetized rat.
In anesthetized rats treated with guanethidine, the pylorus was ligated. A catheter was inserted into the stomach via the mouth and anchored by a ligature around the cervical oesophagus. The catheter was used for instillation into the stomach of a fixed volume (9 ml) of either isotonic or 1 M NaCl and for the recording of intragastric pressure. Neurogenic modulation of gastric motility caused by either solution was analysed by studying the effect of the systemic administration of the ganglionic blocker hexamethonium on gastric tone and on phasic motor activity. Gastric motility was not significantly changed by hexamethonium in the animals that had been subjected to isotonic NaCl. After intragastric treatment with 1 M NaCl, however, hexamethonium caused increased gastric tone and decreased phasic motor activity. An analysis of these results suggests that 1 M NaCl activated vagal non-adrenergic, non-cholinergic relaxatory and cholinergic excitatory motor neurons, respectively. These chemically induced modulations of gastric motility were dependent on the spinal cord and, most probably, were due to activation of the mucosal sensory endings of the splanchnic nerves, leading to reflex spinovagal motor adjustments.
Delbro
D
D
Dept. of Physiology, University of Gothenburg, Sweden.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D005730:Ganglionic Blockers / Q000494:pharmacology; D005753:Gastric Mucosa / Q000187:drug effects / Q000294:innervation*; D005769:Gastrointestinal Motility / Q000187:drug effects*; D006145:Guanethidine / Q000494:pharmacology; D018738:Hexamethonium; D006584:Hexamethonium Compounds / Q000494:pharmacology; D008297:Male; D009619:Nociceptors / Q000187:drug effects*; D051381:Rats; D011919:Rats, Inbred Strains; D012018:Reflex / Q000502:physiology*; D012965:Sodium Chloride / Q000494:pharmacology; D013153:Splanchnic Nerves / Q000187:drug effects; D014630:Vagus Nerve / Q000187:drug effects
D005730:Ganglionic Blockers; D006584:Hexamethonium Compounds; D018738:Hexamethonium; D012965:Sodium Chloride; D006145:Guanethidine