Acute protection against arachidonate toxicity by hydrocortisone and dexamethasone in mice.

1. Pharmacologic doses of hydrocortisone sodium succinate (100 mg/kg) has a rapid protective action against arachidonate-induced mortality in mice when administered intravenously 5 to 60 min before intravenous infusion of arachidonate. 2. Intravenous dexamethasone sodium phosphate (4 mg/kg) has a similar protective effect. 3. The time course of the development of the protective effect of intravenous glucocorticoids suggests that DNA transcription and protein synthesis are not involved in the mechanism of this action. 4. Longer pretreatment with glucocorticoids are required to reduce mortality when subcutaneous or intraperitoneal routes of administration of the steroids used.