Effect of Route of Administration on Protective Action of Corticosterone and Cortisol Against Endotoxin

Abstract

Summary

1. Both cortisol and corticosterone were effective in protecting rats against endotoxin when the steroid hormones were given intracardially at the time of administration of endotoxin. 2. Cortisol was more protective than corticosterone when both were given subcutaneously 24 hours before endotoxin; as the interval between the time of injection of steroid and the time of challenge with endotoxin was decreased, corticosterone was increasingly protective. 3. The rates of disappearance of corticosterone and cortisol from the blood of rats after intracardiac administration of steroid were similar. 4. The evidence indicates that corticosterone is more rapidly mobilized from local tissue sites of deposition than is cortisol and that the difference in the activity of these 2 substances after subcutaneous administration is due in large part to this difference. By inference, the many published differences in the biologic activities of cortisol and corticosterone may be subject to revision when control of this variable has been achieved. 5. Corticotropin and lipoadrenal extract were protective against endotoxin but desoxycorticosterone was not.