Lung liquid clearance and Na,K-ATPase during acute hyperoxia and recovery in rats.
Lung liquid clearance, epithelial permeability for Na+, mannitol and albumin, as well as Na,K-ATPase activity in alveolar type 2 (AT2) cells were studied during the acute and the recovery phase of hyperoxic lung injury. Rats exposed to 100% oxygen for 64 h were studied at 0, 7 and 14 d after removal from the hyperoxic chamber and compared with control rats breathing room air. In the isolated-perfused, liquid-filled rat lung, the albumin flux from the perfusate into the air spaces increased immediately after the oxygen exposure (220 +/- 56 mg/h) and returned to control values (28 +/- 7 mg/h) after 7 and 14 d of recovery. The small solutes (Na+ and mannitol) flux across the alveolar epithelium normalized only after 14 d of recovery in room air. Active Na+ transport and lung liquid clearance were reduced by approximately 45% immediately after oxygen exposure when compared with control values, increased by approximately 56% above control values after 7 d of recovery, and returned to control values after 14 d of recovery. Paralleling these changes the Na,K-ATPase activity decreased by approximately 41% in AT2 cells isolated from rats after 64 h of breathing 100% O2 and increased by approximately 25% after the rats recovered in room air for 7 d. These results suggest that alveolar epithelial Na,K-ATPase may contribute in the recovery from the hyperoxic lung injury by participating in the clearance of lung edema.
Olivera
W G
WG
Michael Reese Hospital, University of Illinois at Chicago 60616, USA.
Ridge
K M
KM
Sznajder
J I
JI
D000418:Albumins / Q000493:pharmacokinetics; D000818:Animals; D001693:Biological Transport, Active / Q000502:physiology; D015824:Blood-Air Barrier / Q000502:physiology; D008297:Male; D008353:Mannitol / Q000493:pharmacokinetics; D010100:Oxygen / Q000009:adverse effects*; D010477:Perfusion; D011650:Pulmonary Alveoli / Q000378:metabolism* / Q000473:pathology; D011654:Pulmonary Edema / Q000209:etiology / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012964:Sodium / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism*; D013047:Specific Pathogen-Free Organisms; D013997:Time Factors
D000418:Albumins; D008353:Mannitol; D012964:Sodium; D000254:Sodium-Potassium-Exchanging ATPase; D010100:Oxygen