Affordable Access

The interaction between reflex apnoea and bradycardia produced by injecting 5-HT into the nodose ganglion of the cat.

Authors
  • Sutton, P M
Type
Published Article
Journal
Pflügers Archiv : European journal of physiology
Publication Date
Mar 01, 1981
Volume
389
Issue
3
Pages
181–187
Identifiers
PMID: 7195005
Source
Medline
License
Unknown

Abstract

The apnoea, accompanied by bradycardia and hypotension caused by injection of 5-Hydroxytryptamine (5-HT) into the vascularly isolated nodose ganglion is characterised by intense electrical activity in the internal intercostal muscles. No such activity was recorded when apnoea was provoked by electrical stimulation of the central end of the superior laryngeal nerve. The cardiac slowing induced by 5-HT was less marked when the superior laryngeal nerve was concomitantly stimulated with an intensity sufficient to inhibit the internal intercostal activity. When central respiratory drive was depressed by hypocapnic ventilation nodose ganglion-induced bradycardia was comparable to that provoked during electrical stimulation of the superior laryngeal nerve in eupnoea. Unlike chemoreceptor-induced bradycardia the cardiac slowing caused by nodose ganglion stimulation was not reduced by "ramp" inflation of the lungs. The results were similar during hypocapnic depression of the "Respiratory Centre". These findings suggest that: (a) central expiratory activity contributes to the bradycardia induced by nodose ganglion stimulation, and (b) the inhibition of bradycardia by lung expansion occurs before the neural impulses reach the nucleus ambiguus but does not involve the central respiratory neurones.

Report this publication

Statistics

Seen <100 times