Aldosterone regulates Na,K-ATPase and increases lung edema clearance in rats.
Aldosterone increases the Na,K-ATPase function in renal cells involved in active Na(+) transport. Because the alveolar type 2 (AT2) cells participate in active Na(+) transport, we studied whether aldosterone regulates the Na,K-ATPase in rat AT2 cells and whether aldosterone delivered by aerosols to spontaneously breathing rats affects edema clearance in a model of isolated-perfused lungs. The AT2 cells treated with aldosterone had increased Na,K-ATPase beta1-subunit mRNA and protein, which was associated with a 4-fold increase in the Na,K-ATPase hydrolytic activity and the ouabain-sensitive (86)Rb(+) uptake. In physiologic experiments, 24 h after aldosterone was delivered by aerosols to the rat air spaces, the active Na(+) transport and lung edema clearance increased by approximately 53% as compared with control rats and rats in which saline aerosols were delivered. The data suggest that increased active Na(+) transport and lung edema clearance induced by aldosterone is probably due to Na,K-ATPase regulation in alveolar epithelial cells. Conceivably, aldosterone may be used as a strategy to increase lung edema clearance.
Olivera
W G
WG
Pulmonary and Critical Care Medicine Division, Northwestern University Medical School, Chicago, IL 60611, USA.
Ciccolella
D E
DE
Barquin
N
N
Ridge
K M
KM
Rutschman
D H
DH
Yeates
D B
DB
Sznajder
J I
JI
D000450:Aldosterone / Q000494:pharmacology / Q000502:physiology*; D000818:Animals; D015633:Extravascular Lung Water / Q000378:metabolism; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects; D008297:Male; D010477:Perfusion; D011650:Pulmonary Alveoli / Q000503:physiopathology*; D011654:Pulmonary Edema / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000235:genetics / Q000378:metabolism*
D000450:Aldosterone; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase