Journal of Clinical Endocrinology & Metabolism, Vol 58, 947-949, Copyright © 1984 by Endocrine Society

ARTICLES

Inhibition by etomidate of steroidogenesis in isolated bovine adrenal cells

CJ Kenyon, J Young, CE Gray and R Fraser

Adverse side effects of the anaesthetic etomidate have been indirectly linked with inhibition of adrenocorticoid synthesis. The present in vitro study has shown that this is a direct effect and indicated which biosynthetic reactions are affected by etomidate. Isolated bovine adrenocortical cells were incubated with and without 10(-8)M ACTH and with increasing doses of etomidate (0-625 ng/ml). ACTH-stimulated cortisol synthesis was significantly inhibited by a concentration of etomidate (25 ng/ml), which is much less than therapeutic plasma levels (100-500 ng/ml). Both basal and ACTH stimulated synthesis of cortisol, progesterone, 17 alpha hydroxyprogesterone and corticosterone were inhibited by 625 ng etomidate/ml whereas deoxycorticosterone output was more than doubled with this dose of anaesthetic. These observations suggest that etomidate inhibits mitochondrial cytochrome P450-dependent hydroxylation reactions in the adrenal steroidogenic pathway.