Oxygen free radical formation by rat hepatocytes during postanoxic reoxygenation: scavenging effect of albumin.
Free radical formation and reoxygenation injury were studied in rat hepatocytes perfused with Krebs-Henseleit bicarbonate buffer containing 1% or no albumin. After 2, 2.5, or 3 h of anoxia followed by 1 h reoxygenation in the absence of albumin, free radical formation assessed by low-level chemiluminescence and cell injury measured by lactate dehydrogenase (LDH) release and by trypan blue uptake increased proportionately. Chemiluminescence increased 4- to 7-fold, LDH release and trypan blue uptake increased 1.5- to 2-fold, compared with the end of anoxia. With 1% albumin, there was no increase in free radical formation during reoxygenation, and LDH release returned to control levels. There was a linear relation between the increase in chemiluminescence and the rise in LDH release (r2 = 0.83) and the increase in trypan blue uptake (r2 = 0.80), suggesting that free radical formation during reoxygenation is responsible for the cell injury. These experiments demonstrate that freshly isolated hepatocytes produce oxygen free radicals detectable by low-level chemiluminescence and that reoxygenation injury occurs after a relatively short period of anoxia (2-3 h). Albumin acts as a free radical scavenger, suppresses the release of reactive oxygen species, and significantly reduces reoxygenation injury.
Caraceni
P
P
Department of Physiology, University of Pittsburgh School of Medicine, Pennsylvania 15261.
Gasbarrini
A
A
Van Thiel
D H
DH
Borle
A B
AB
D000332:Aerobiosis; D000818:Animals; D016166:Free Radical Scavengers; D000860:Hypoxia / Q000378:metabolism*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000378:metabolism*; D008163:Luminescent Measurements; D008297:Male; D010100:Oxygen / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017382:Reactive Oxygen Species / Q000378:metabolism*; D012016:Reference Values; D012709:Serum Albumin / Q000494:pharmacology*; D014343:Trypan Blue / Q000493:pharmacokinetics
D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D012709:Serum Albumin; D007770:L-Lactate Dehydrogenase; D014343:Trypan Blue; D010100:Oxygen