Differential control of ventilation among inbred strains of mice

C. G. Tankersley, R. S. Fitzgerald, S. R. Kleeberger

Research output: Contribution to journalArticle

Abstract

The role genetic factors play in ventilatory control was examined by challenging eight inbred strains of mice to acute hypercapnia under normoxic and hypoxic conditions. Age-matched mice were exposed for 3-5 min to inspired gases of the following composition (FI(CO2):FI(O2)) 0.03:0.10, 2) 0.03:0.21, 3) 0.08:0.10, and 4) 0.08:0.2], with intermittent room air exposures. Breathing frequency (f) and tidal volume (VT) of unanesthetized, unrestrained mice were assessed by whole body plethysmography. During room air breathing, significant (P < 0.01) interstrain differences were noted in the pattern, but minute ventilation (V̇E) did not differ among the strains. Relative to room air, mild hypercapnia with hypoxia (0.03:0.10) significantly (P < 0.01) elevated V̇E in each strain, and the percent increase in V̇E of the DBA/2J strain was significantly (P < 0.05) greater than the other strains. The ventilatory response to these conditions was achieved primarily by a significant (P < 0.01) increase in f among the strains. During severely hypercapnic normoxia (0.08:0.21) and hypoxia (0.08:0.10), the increase in V̇E was significantly (P < 0.01) greatest in the C57BL/6J (B6) mice and least in the C3H/HeJ (C3) mice. The difference in hypercapnic V̇E between B6 and C3 strains was largely due to a significantly (P < 0.01) greater increase in VT by B6 mice. On the assumption that environmental factors were identical, these data suggest that genetic determinants govern interstrain variation in the magnitude and pattern of breathing during hypoxia and hypercapnia. Moreover, hypoxic and hypercapnic ventilatory responses appear to be influenced by different genetic mechanisms.

Original languageEnglish (US)
Pages (from-to)R1371-R1377
JournalAmerican Journal of Physiology - Regulatory Integrative and Comparative Physiology
Volume267
Issue number5 36-5
DOIs
StatePublished - 1994

Keywords

  • breathing pattern
  • genetic control
  • hypercapnic ventilation
  • hypoxic ventilation

ASJC Scopus subject areas

  • Physiology
  • Physiology (medical)

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