Na+/K+ ATPase in lower airway epithelium from cystic fibrosis and non-cystic-fibrosis lung.
The basolateral Na+/K+ ATPase plays a critical role in sodium reabsorption across airway epithelium. Nasal epithelium shows increased Na+/K+ ATPase activity in cystic fibrosis (CF) but Na+/K+ ATPase has not been characterized in human lung epithelium or compared in CF and normal lung. We measured 3[H] ouabain binding and Na+/K+ ATPase activity in human tracheal epithelium and compared Na/K ATPase activity in bronchial epithelium in CF and control subjects. In tracheal epithelium Na+/K+ ATPase pumps were abundant and of high 3[H] ouabain affinity (Kd 4.7 nM, Bmax 38 pmol/mg) and Na+/K+ ATPase activity was 55 +/- 8 nmol/mg protein/min. Bronchial epithelial Na+/K+ ATPase activity was twofold higher in CF patients than in controls. The increased Na+/K+ ATPase activity may contribute to the increased sodium reabsorption seen in cystic fibrosis.
Peckham
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Respiratory Medicine Unit, City Hospital, Nottingham, England.
Holland
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Range
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Knox
A J
AJ
D000293:Adolescent; D000328:Adult; D001665:Binding Sites; D001980:Bronchi / Q000201:enzymology* / Q000378:metabolism; D003550:Cystic Fibrosis / Q000201:enzymology* / Q000378:metabolism; D004848:Epithelium / Q000201:enzymology / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010042:Ouabain / Q000378:metabolism; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D014132:Trachea / Q000201:enzymology* / Q000378:metabolism
D010042:Ouabain; D000254:Sodium-Potassium-Exchanging ATPase