[Biological standardization of the gonadotropin-inhibiting factor]

The authors suggest a method of quantitative determination of the goandotropin-inhibiting factor in the urine; the principle of calculation of the activity of the standard preparation of the gonadotropin-inhibiting factor is presented. Investigation of the activity of the inhibitor in the individual portions of the urine of 6-8-year-old children demonstrated that the method of obtaining, testing and calculating the activity of the gonadotropin-inhibiting factor reflected quite adequately the biological activity of the extracts of child urine preventing the action of crude gonadotropins.