Steroid hydroxylase induction in cultured human lymphocytes: effects of the menstrual cycle

Steroid hydroxylases (SAH) are inducible in cultured human lymphocytes following treatment with estradiol-17beta. The enzyme systems induced are carbon monoxide sensitive and convert estradiol-17beta to a metabolite chromatographically indistinguishable from estriol. The level of inducibility of SAH varies drastically over a normal menstrual cycle with maximum induction in the late follicular phase and minimum induction during the luteal phase. The use of an oral contraceptive containing both a synthetic progestogen and ethynyl estradiol reduced SAH induction levels to those typically seen during the luteal phase of the menstrual cycle.