Sex-Specific Effects of Daily Gavage with a Mixed Progesterone and Glucocorticoid Receptor Antagonist on Hypoxic Ventilatory Response in Newborn Rats

  • Stéphanie Fournier
  • Van Diep Doan
  • Vincent JosephEmail author
Conference paper
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 758)


We tested the hypothesis that daily gavage with mifepristone, a mixed progesterone/glucocorticoid receptor antagonist would alter hypoxic ventilatory response (HVR) in newborn male and female rats. Rats were treated with mifepristone (40µg/g/day), or vehicle between postnatal days 3–12, and used at 10–12 days of age to record baseline ventilatory and metabolic values using whole body plethysmography. HVR was tested by exposing the animals to 14% and 12% O2 for 20 minutes each. HVR was enhanced by mifepristone treatment, mainly due to an effect on tidal volume that remained higher in mifepristone treated rats during both levels of hypoxic exposure. This effect was sex-specific being apparent only in male rats. In Vehicle treated rats, HVR was higher in females than in males, which was also due to a higher tidal volume in hypoxia (at 14 and 12% O2). We conclude that the activity of the progesterone and/or glucocorticoid receptors modulates respiratory control in rat pups, and that these effects are different in males and females.


Newborn rats Gavage Mifepristone Steroid receptor antagonist Progesterone Glucocorticoid Hypoxic ventilatory response Whole body plethysmography 


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Copyright information

© Springer Science+Business Media Dordrecht 2012

Authors and Affiliations

  • Stéphanie Fournier
    • 1
  • Van Diep Doan
    • 1
  • Vincent Joseph
    • 1
    Email author
  1. 1.Department of PediatricsLaval University, Centre de Recherche CHUQ, Hôpital St-François d’AssiseQuebecCanada

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