[Inhibin-like activity in human ovarian follicular fluid (author's transl)]

A steroid-free proteinaceous substance with inhibin-like activity has been extracted from human ovarian follicular fluid by alcohol precipitation. This substance was capable of inhibiting the ovarian weight increase of hCG-treated immature female rats and also of suppressing the post-castration rise of serum FSH levels in immature male rats. Follicular fluid from small follicls obtained from regularly cycling women was--on the basis of protein- found to be more active than cystic follicular fluid obtained from a premenopausal woman. The possible role of inhibin in the regulation of human ovarian cycle has been discussed.