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Polyethylene glycol-attached antioxidant enzymes decrease pulmonary oxygen toxicity in rats
C W White1, J H Jackson, A Abuchowski
1Department of Pediatrics, University of Colorado School of Medicine, Denver 80262.
Journal of Applied Physiology (Bethesda, Md. : 1985)
|February 1, 1989
Summary
Polyethylene glycol (PEG)-attached superoxide dismutase and catalase (PEG-SOD + PEG-CAT) significantly extended survival in rats exposed to hyperoxia. PEG-SOD + PEG-CAT also reduced hyperoxia-induced lung injury.
Area of Science:
- Biochemistry
- Toxicology
- Physiology
Background:
- Hyperoxia (100% O2) induces acute oxidative lung injury.
- Antioxidant enzymes like superoxide dismutase (SOD) and catalase (CAT) combat oxidative stress.
- Polyethylene glycol (PEG) conjugation can modify enzyme properties.
Purpose of the Study:
- To evaluate the protective effects of PEG-conjugated SOD and CAT against hyperoxia-induced lung injury in rats.
- To compare the efficacy of PEG-enzymes with other antioxidant strategies.
Main Methods:
- Rats were pretreated with PEG-SOD + PEG-CAT, saline, or other control solutions before continuous exposure to hyperoxia.
- Survival rates and indicators of lung injury (lung oxidized glutathione, pleural effusions, albumin concentration) were assessed.
Main Results:
- PEG-SOD + PEG-CAT pretreatment significantly increased rat survival time compared to saline or inactivated PEG-enzyme controls.
- PEG-SOD + PEG-CAT treatment reduced markers of hyperoxia-induced lung injury.
- PEG itself showed some hydroxyl radical scavenging activity in vitro.
- PEG-enzymes were less protective than endogenous or liposomal antioxidant strategies.
Conclusions:
- PEG-conjugated SOD and CAT offer protection against hyperoxia-induced lung injury and increase survival.
- While PEG-enzymes provide a benefit, other antioxidant delivery methods may be more effective.
- PEG may contribute to protection through direct radical scavenging properties.