Attenuated Hering-Breuer inflation reflex 4 years after pulmonary vagal denervation in ponies. J Appl Physiol (1985) 1990 Dec;69(6):2163-7
Date
12/01/1990Pubmed ID
2127593DOI
10.1152/jappl.1990.69.6.2163Scopus ID
2-s2.0-0025572636 (requires institutional sign-in at Scopus site) 3 CitationsAbstract
The purpose of this study was to determine whether there was any recovery of the Hering-Breuer inflation reflex in ponies between 2-4 wk and 3-4 yr after hilar nerve denervation (HND). Under anesthesia and before HND, airway occlusion after a 3-liter lung inflation lengthened the subsequent occluded breath by nearly 10 times the control breath duration. Between 2 wk and 3-4 yr after HND, this maneuver increased the duration of the occluded breath by only 2.5 times the control breath duration. Also under anesthesia, the airway was occluded at end expiration. This maneuver increased the duration of the subsequent inspiratory effort by 71% in hilar nerve intact ponies but by only 20-25% 2-4 wk and 3-4 yr after HND. For both tests, the pre- and post-HND differences were statistically significant (P less than 0.05), but there were no significant differences (P greater than 0.10) between 2-4 wk and 3-4 yr post-HND. In awake ponies, at rest and during mild and moderate treadmill exercise, breathing frequency was generally lower and inspiratory time was greater after relative to before HND. The inspiratory time-to-total cycle duration ratio was consistently increased by 0.10-0.15 after HND (P less than 0.05). There was no significant change in this ratio between 2-4 wk and 3-4 yr post-HND (P greater than 0.10). We conclude that the surgical procedure for HND used in this study does not permit any significant reinnervation, and there are no significant changes within the ventilatory control system to compensate for loss of hilar nerve afferents.
Author List
Forster HV, Pan LG, Flynn C, Bisgard GEAuthor
Hubert V. Forster PhD Professor in the Physiology department at Medical College of WisconsinMESH terms used to index this publication - Major topics in bold
AnimalsCarbon Dioxide
Denervation
Horses
Hydrogen-Ion Concentration
Inhalation
Lung
Male
Orchiectomy
Oxygen
Reflex
Respiration
Respiratory Muscles
Time Factors
Vagus Nerve