[The clinical value of radioimmunological oestradiol assays in the diagnosis of menstrual disorders. Evidence suggesting the presence of an ovarian "inhibin" (author's transl)].

The radioimmunoassay of oestradiol 17 beta (E2) from the blood without chromatography was evaluated in regard to the diagnosis of menstrual cycle disturbances. Two significantly different classes were distinguished, viz. 1. Women with higher E2 values, consisting of three groups: normal controls, cases of oligomenorrhoea, and WHO II (normogonadotropic, clomiphen-positive amenorrhoea). 2. Women with lower E2 values, consisting of two groups: WHO I (hypogonadotropic, clomiphen-negative amenorrhoea) and WHO III (hypergonadotropic amenorrhoea). Within these classes no significant differences were found between the groups. Only values below 43.1 pg/ml can be assigned with 95% certainty to the low-value class and only values above 108.8 pg/ml can be assigned with 95% certainty to the high-value class. The fact that 40% of all E2 values in hypergonadotropic, (i.e. ovarian) amenorrhoea fell within the range of the double standard deviation of the normal group and, likewise, the fact that physiological doses of oestrogen cannot reduce postmenopausal FSH to the level found in women of reproductive age suggest that E2 is not the only FSH-reducing factor, which leads us to postulate the existence of an ovarian "inhibin".