Evaluation of reexpansion pulmonary edema following unilateral pneumothorax in rabbits and the effect of superoxide dismutase.
We investigated the lung injury that occurs following reexpansion of a unilateral pneumothorax and determined the effect of superoxide dismutase (SOD) infused immediately prior to reexpansion on this injury. After 7 days of at least 80% right pneumothorax, rabbits received intravenous infusions of either SOD (n = 7), heat-inactivated SOD (n = 1), or vehicle (n = 7) immediately before lung reexpansion. Lung injury was assessed by measuring the systemic white cell counts, pulmonary blood volumes, extravascular albumin, extravascular lung water, wet/dry weight ratios, and histology 2 h after reexpansion. The reexpanded lung showed increased extravascular albumin, extravascular lung water and wet/dry weight ratios with decreased blood volumes compared to the uninjured lung. SOD delayed the onset of leukopenia and neutropenia at 3 and 7 min after reexpansion, but the white cell counts had decreased to the same level in both groups by 30 min. SOD had no effect on the degree of injury after 2 h. While a single bolus of SOD given immediately before reexpansion delayed the onset of this injury, it did not affect the injury that subsequently developed in the lung.
University of British Columbia, Pulmonary Research Laboratory, Vancouver, Canada.
C M
CM
Doerschuk
M F
MF
Allard
M J
MJ
Oyarzun
D000418:Albumins / Q000378:metabolism; D000818:Animals; D001810:Blood Volume / Q000502:physiology; D001834:Body Water / Q000378:metabolism; D005260:Female; D005609:Free Radicals; D007970:Leukopenia / Q000209:etiology / Q000517:prevention & control; D009503:Neutropenia / Q000209:etiology / Q000517:prevention & control; D011030:Pneumothorax / Q000150:complications*; D011654:Pulmonary Edema / Q000209:etiology* / Q000473:pathology / Q000517:prevention & control; D011817:Rabbits; D013482:Superoxide Dismutase / Q000494:pharmacology*
D000418:Albumins; D005609:Free Radicals; D013482:Superoxide Dismutase