Abstract
Pentobarbital was reported to have a protective effect against oxygen toxicity at high pressures in rat lungs. However, its effect under normobaric state is not known. We administered pentobarbital (20mg/kg, i.p., every 24h) for 4 days prior to 95% O2 or air exposure to the adult rats and compared the effects on the lung, plasma, and liver antioxidant systems with control (non-treated) rats. We determined superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GP) as the activity of antioxidant systems, thiobarbituric acid reactant substance as the extent of lipid peroxidation, and α-tocopherol on lung tissues, plasma, and liver. Antioxidant enzymes did not change significantly after pentobarbital pretreatment except CAT in liver. After O2 exposure for 48h, antioxidant enzymes of both control and pentobarbital pretreated groups did not change significantly. We observed a significant increase in lipid peroxide formation in liver in both groups after O2 exposure, and the increase was marked in the pentobarbital pretreated group.
The results suggest that pentobarbital may not have a protective effect aganist oxygen toxicity in rat lung under normobaric condition, and the combination of pentobarbital and high concentration of oxygen may cause liver damage.
