Terbutaline increases open channel density of epithelial sodium channel (ENaC) in distal lung.
Neonatal and adult vertebrate respiration is facilitated by alveolar fluid and sodium (Na+) absorption driven by apical sodium channels (ENaC). ENaC are characterized in Xenopus laevis lung (XLL) epithelia using voltage clamping and fluctuation analysis to non-invasively examine macroscopic transepithelial current and resistance (I(SC), R(T)), single channel current (i(Na)) and total channel density (N(T)) responses to a beta adrenergic agonist (Terbutaline). Terbutaline addition to the basolateral bath of XLL increased Na entry to > 200% of control reflecting a doubling of open channel density (N(o). These data are consistent with the notion that XLL can serve as a useful model for investigation of distal lung ENaC response to agents of physiological interest.
The Johns Hopkins University, School of Nursing, Baltimore, MD 21205, USA. lynnbc@son.jhmi.edu
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Baxendale-Cox
D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000818:Animals; D053503:Epithelial Sodium Channels; D008168:Lung / Q000187:drug effects*; D018408:Patch-Clamp Techniques; D012044:Regression Analysis; D012964:Sodium / Q000378:metabolism; D015222:Sodium Channels / Q000378:metabolism*; D013726:Terbutaline / Q000494:pharmacology*; D014223:Triamterene / Q000494:pharmacology; D014982:Xenopus laevis
D000318:Adrenergic beta-Agonists; D053503:Epithelial Sodium Channels; D015222:Sodium Channels; D012964:Sodium; D013726:Terbutaline; D014223:Triamterene