Airway expression of the epithelial sodium channel α-subunit correlates with cortisol in term newborns.

Autor: Janér C; Children's Hospital, Pediatric Research Center, Helsinki University Central Hospital, Biomedicum Helsinki 2 U E104b, Helsinki, Finland. cecilia.janer@hus.fi, Pitkänen OM, Helve O, Andersson S
Jazyk: angličtina
Zdroj: Pediatrics [Pediatrics] 2011 Aug; Vol. 128 (2), pp. e414-21. Date of Electronic Publication: 2011 Jul 18.
DOI: 10.1542/peds.2011-0167
Abstrakt: Background: Glucocorticoids have profound effects on lung maturation and function. In in vitro and animal models, they induce epithelial sodium channels (ENaCs) in the airway epithelium, a process that is important to perinatal lung fluid clearance.
Objective: The objective of this study was to determine whether, in newborn infants, airway ENaC expression is associated with cortisol concentrations.
Methods: Cord blood, saliva, and cells from nasal epithelium were obtained from 69 infants delivered at term. Epithelial and saliva sampling was repeated 3 times: <3, 22 to 29, and 40 to 54 hours postnatally. Cortisol, thyrotropin, and free triiodothyronine concentrations were measured with immunoassays, and expression of α-ENaC and β-ENaC was quantified with real-time reverse-transcriptase polymerase chain reaction.
Results: Expression of α-ENaC <30 minutes postnatally correlated with cord plasma cortisol in infants delivered by elective cesarean delivery. In addition, in the total study population <2 hours postnatally, α-ENaC expression correlated with salivary cortisol concentrations. β-ENaC expression, in contrast, showed no association with cortisol concentrations. A significant decrease in β-ENaC expression during the first postnatal day was revealed, whereas timing of the peak in α-ENaC expression seemed to depend on mode of delivery.
Conclusions: These results support a role in humans for endogenous glucocorticoids in the regulation of airway ion transport. This finding may be a physiologic mechanism mediating pulmonary adaptation in the newborn infant.
Databáze: MEDLINE