Effect of in vivo corticosteroids on Na+ transport across airway epithelia.
We have investigated the role in vivo of mineralocorticoid and glucocorticoid hormones in regulating the rate of electrogenic amiloride-sensitive Na+ absorption across murine airway tissue studied in vivo (nasal potential difference) and in vitro (Ussing chambers). We found that elevating the plasma aldosterone concentration 10-fold (low-Na+ diet) had no significant effect on amiloride-sensitive Na+ absorption across tracheal or nasal epithelia. High doses of dexamethasone for 1 wk likewise did not change the rate of amiloride-sensitive Na+ absorption across airway epithelia. In contrast, both hormonal manipulations elevated the rate of colonic Na+ absorption. Furthermore, adrenalectomy (both normal and cystic fibrosis mice) also failed to alter Na+ absorption across airway epithelia. We conclude that, in vivo, neither the mineralocorticoid nor the glucocorticoid hormones significantly regulate the rates of amiloride-sensitive electrogenic Na+ absorption across airway epithelia in the adult mouse.
Grubb
B R
BR
Cystic Fibrosis/Pulmonary Research and Treatment Center, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7248, USA.
Boucher
R C
RC
D000305:Adrenal Cortex Hormones / Q000494:pharmacology / Q000502:physiology; D000315:Adrenalectomy; D000450:Aldosterone / Q000097:blood*; D000616:Aminoglutethimide / Q000494:pharmacology; D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D003106:Colon; D003345:Corticosterone / Q000097:blood; D003550:Cystic Fibrosis / Q000235:genetics / Q000503:physiopathology*; D003907:Dexamethasone / Q000494:pharmacology*; D004039:Diet, Sodium-Restricted; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D008815:Mice, Inbred Strains; D008817:Mice, Mutant Strains; D009092:Mucous Membrane / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology; D009666:Nose / Q000502:physiology; D012964:Sodium / Q000378:metabolism*; D014132:Trachea / Q000502:physiology
D000305:Adrenal Cortex Hormones; D000616:Aminoglutethimide; D000450:Aldosterone; D003907:Dexamethasone; D012964:Sodium; D003345:Corticosterone