Action of anti-inflammatory agents on endotoxin-induced lung inflammation in mice

¹ Department of Biochemistry, Schering Corporation, Bloomfield, New Jersey

The instillation of Escherichia coli endotoxin (lipopolysaccharide) intranasally into mice produced severe lung lesions and a substantial increase in lung weight. Lung inflammation was maximal about 3 days after endotoxin instillation. Intraperitoneal injection of prednisone, cortisone and hydrocortisone sharply suppressed the lung inflammation. Five milligrams of prednisone produced a maximal anti-inflammatory effect when injected 24 and 48 hours after the endotoxin. Administration of large doses of Butazolidin also produced a modest effect on the lung inflammation. It is suggested that locally applied endotoxin alters blood vessel permeability of the lungs, resulting in hemorrhage, edema and exudation. The anti-inflammatory steroids reverse or inhibit this effect, perhaps by maintaining the integrity of the capillaries. Possible use and significance of this experimental anti-inflammatory system is discussed.