Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2007-11-5
pubmed:abstractText
Congenital central hypoventilation syndrome (CCHS) is a rare disease with variable severity, generally present from birth and chiefly characterized by impaired chemosensitivity to hypercapnia. The main cause of CCHS is a mutation in the PHOX2B gene, which encodes a transcription factor involved in the development of autonomic medullary reflex pathways. Temperature regulation is abnormal in many patients with CCHS. Here, we examined whether ambient temperature influenced CO(2) sensitivity in a mouse model of CCHS. A weak response to CO(2) at thermoneutrality (32 degrees C) was noted previously in 2-day-old mice with an invalidated Phox2b allele (Phox2b+/-), compared with wild-type littermates. We exposed Phox2b+/- pups to 8% CO(2) at three ambient temperatures (TAs): 29 degrees C, 32 degrees C, and 35 degrees C. We measured breathing variables and heart rate (HR) noninvasively using a novel whole body flow plethysmograph equipped with contact electrodes. Body temperature and baseline breathing increased similarly with TA in mutant and wild-type pups. The hypercapnic ventilatory response increased linearly with TA in both groups, while remaining smaller in mutant than in wild-type pups at all TAs. The differences between the absolute increases in ventilation in mutant and wild-type pups become more pronounced as temperature increased above 29 degrees C. The ventilatory abnormalities in mutant pups were not associated with significant impairments of heart rate control. In both mutant and wild-type pups, baseline HR increased with TA. In conclusion, TA strongly influenced the hypercapnic ventilatory response in Phox2b+/- mutant mice. These findings suggest that abnormal temperature regulation may contribute to the severity of respiratory impairments in CCHS patients.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0363-6119
pubmed:author
pubmed:issnType
Print
pubmed:volume
293
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
R2027-35
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Effects of temperature on ventilatory response to hypercapnia in newborn mice heterozygous for transcription factor Phox2b.
pubmed:affiliation
Institut National de la Santé et de la Recherche Médicale, U676, Hôpital Robert Debré, Paris, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't