EFFECT OF INTRATRACHEAL DEXAMETHASONE ON OLEIC ACID-INDUCED LUNG INJURY IN THE RAT

The therapeutic efficacy of single-dose intratracheal dexamethasone (2 .5 mg/kg) in oleic acid-induced acute lung injury in the rat was estab lished by showing significant improvement in bronchoalveolar lavage pa rameters and lung compliance at 24 h after oleic acid as compared with animals not treated with oleic acid. An equivalent dose of intraperit oneal dexamethasone demonstrated no therapeutic benefit at 24 h after oleic acid. The therapeutic effect of this single-dose intratracheal d examethasone regimen was accompanied by recovery to normal bronchoalve olar parameters and lung compliance at 7 days, in contrast to previous observations made with high-dose sustained intraperitoneal dexamethas one (4 mg/kg for 7 days). This improved benefit:toxicity ratio of intr atracheal dexamethasone compared with systemic dexamethasone may be du e to enhanced topical anti-inflammatory potency relative to systemic p otency and toxicity.