The Effect of Prenatal Dexamethasone Treatment on Pulmonary Antioxidant System in Newborn Rats during Prolonged High O2 Exposure. |
In Kyung Sung, So Young Kim |
Department of Pediatrics, Catholic University of Korea, Seoul, Korea. |
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Abstract |
PURPOSE To evaluate the effect of prenatally treated dexamethasone on pulmonary antioxidant enzyme system and survival rate in newborn rats during prolonged high oxygen exposure. METHODS The wet lung weight/dry lung weight ratio, malondialdehyde content, superoxide dismutase activity, pathologic evidence of lung injury and the survival rate in dexamethasone pretreated term newborn rats (DEX group) were compared to saline pretreated newborn rats (control group) during prolonged high oxygen exposure. Exposures to hyperoxia (>95% oxygen) were continuous for 10 days after birth. RESULTS The prenatal dexamethasone treated pups showed significantly decreased wet lung weight/dry lung weight ratio, malondialdehyde concentr The composite percentage of survival was significantly greater in the prenatal dexamethasone pups from day 7 to day 10 in hyperoxia. CONCLUSION The ability to tolerate prolonged exposure to hyperoxia was improved by prenatal dexamethasone treatment in newbom rat, showing less evidence of pulmonary oxygen toxicity. This protective effect of prenatal dexamethasone might have related to the more pronounced antioxidant enzyme response to hyperoxia. |
Key Words:
Dexamethasone; Newborn; Antioxidant Enzyme; Hyperoxia |
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