Effects of Cortisol and Adrenalectomy on Induction of Interferon by Endotoxin.

Abstract
Summary The administration of 1 to 5 mg of cortisol to 1 kg rabbits markedly suppressed interferon production by E. coli endo-toxin. Single doses of cortisol, up to 25 mg, did not decrease circulating interferon levels following inoculations with Newcastle disease virus. This type of interferon was only partially suppressed with multiple injections of 250 mg. Thus, administered cortisol inhibited more readily the production of endotoxin-in-duced interferon than the virus-induced counterpart. Adrenalectomy markedly potentiated the production of interferon by endotoxin. Adrenalectomized rabbits inoculated with endotoxin produced serum interferon to a mean titer of 1:388, while the mean titer in control animals was 1:28, suggesting that endogenous steroids suppress the interferon esponse to endotoxin. Mrs. Linda Carcione offered excellent technical assistance. One of us (Miss Catherine DeAngelis) was a recipient of a summer research fellowship under NIH grant 5416-05.