Effect of corticosteroids on the toxic pulmonary oedema induced by nitrogen dioxide inhalation in the rat.

Various corticoid derivatives administered by inhalation or intraperitoneally were investigated for a preventive effect on the pulmonary oedema of the rat induced by the 30-min inhalation of 100-105 ppm NO2. After inhalational administration in the form of an aqueous aerosol, dexamethasone-21-isonicotinate showed a considerably greater efficacy than beclomethasone-17,21-dipropionate or dexamethasone-21-dihydrogen phosphate. With prophylactic intraperitoneal administration dexamethasone (free alcohol), dexamethasone-21-dihydrogen phosphate and 6 alpha-methylprednisolone-21-dihydrogen succinate had to be given in much higher doses than dexamethasone-21-isonicotinate to achieve the same effects on the toxic pulmonary oedema.