Laryngeal constriction during hypoxic gasping and its role in improving autoresuscitation in two mouse strains

J Appl Physiol (1985). 2009 Apr;106(4):1223-6. doi: 10.1152/japplphysiol.91192.2008. Epub 2009 Jan 22.

Abstract

Laryngeal closure following hypoxic gasps has been documented, but its efficacy in improving autoresuscitation capacity is unknown. We studied SWR/J mice who normally cannot autoresuscitate and the C57/BLJ strain who can. We evaluated the effects of elevated end-inspiratory lung volume immediately following a gasp. We compared upper airway-intact mice with tracheostomized mice in which the vocal cords are bypassed. We used the techniques of repeated autoresuscitate trials to test autoresuscitation capability. Both SWR/J and C57/BLJ mice could maintain elevated lung volume immediately after a gasp (breath holding). Such breath holding increased autoresuscitation ability in C57/BLJ mice but did not in SWR/J mice. In SWR/J mice, the duration of the breath holds was less than that in the C57/BLJ mice. These findings indicate that gasp-associated breath holding improves autoresuscitation capability during repeated autoresuscitation trials. Also, they show that SWR/J mice have a deficiency in central nervous system mechanisms regulating glottic closure during hypoxic gasping.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • Animals
  • Constriction
  • Electrophysiology
  • Hypoxia / physiopathology*
  • Larynx / physiology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Inbred Strains
  • Peak Expiratory Flow Rate
  • Respiratory Mechanics / physiology
  • Resuscitation*
  • Tracheostomy