Effects of postnatal dexamethasone on oxygen toxicity in neonatal rats.

We investigated the effect of timing of early postnatal dexamethasone on survival of hyperoxia-exposed neonatal rats. Pups <24 h old were treated with a tapering course of dexamethasone or saline beginning either prior to exposure (day 0), or after 2, 4, or 6 days of > or =98% O2 (n=11-14) or air (n=8-11). Exposures were continued for 14 days.

Endotoxin protection from oxygen toxicity: effect on pulmonary neutrophils and L-selectin.

The mechanisms by which sublethal doses of endotoxin protect against hyperoxic lung injury are not completely understood. We hypothesized that endotoxin treatment would result in a decreased inflammatory response to hyperoxia and that this would be accompanied by activation of neutrophils (as evidenced by loss of L-selectin) in the peripheral circulation. Adult rats were injected with endotoxin 0.