Reduced hypoxic ventilatory response in newborn mice knocked-out for the progesterone receptor.

TitleReduced hypoxic ventilatory response in newborn mice knocked-out for the progesterone receptor.
Publication TypeJournal Article
Year of Publication2014
AuteursPotvin, C, Rossignol, O, Uppari, NP, Dallongeville, A, Bairam, A, Joseph, V
JournalExp Physiol
Volume99
Issue11
Pagination1523-37
Date Published2014 Nov
ISSN1469-445X
KeywordsAnimals, Animals, Newborn, Apnea, Body Weight, Female, Genotype, Hypoxia, Male, Mice, Mice, Knockout, Oxygen Consumption, Plethysmography, Whole Body, Receptors, Progesterone, Respiratory Function Tests, Respiratory Mechanics, Sex Characteristics
Abstract

Recent studies showed that progesterone stimulates the hypoxic ventilatory response and may reduce apnoea frequency in newborn rats, but so far we still do not know by what mechanisms and whether endogenous progesterone might contribute to respiratory control in neonates. We therefore determined the role of the nuclear progesterone receptor (PR; member of the steroid receptor superfamily) by using wild-type (WT) and PR knock-out (PRKO) mice at postnatal days (P) 1, 4 and 10. We measured the hypoxic ventilatory response (14 and 12% O2, 20 min each) and apnoea frequency in both male and female mice by using whole-body plethysmography. In response to hypoxia, WT male mice had a marked hypoxic ventilatory response at P1 and P10, but not at P4. At P1 and P10, PRKO male mice had a lower hypoxic ventilatory response than WT males. Wild-type female mice had a marked hypoxic ventilatory response at P10, but not at P1 and P4. At P1 and P10, PRKO female mice had a lower hypoxic ventilatory response than WT females. In basal conditions, apnoea frequency was similar in WT and PRKO mice at P1, P4 and P10. During hypoxia, apnoea frequency was higher in WT male mice compared with PRKO male mice and WT female mice at P1. We conclude that PR is a key contributor to the hypoxic ventilatory response in newborn mice, but PR deletion does not increase the frequency of apnoea during normoxia or hypoxia.

DOI10.1113/expphysiol.2014.080986
Alternate JournalExp. Physiol.
PubMed ID25172890
Grant ListMOP-102715 / / Canadian Institutes of Health Research / Canada
MOP-119272 / / Canadian Institutes of Health Research / Canada