THE URINARY EXCRETION OF INTERSTITIALCELL AND FOLLICLE-STIMULATING HORMONE ACTIVITY DURING THE NORMAL MENSTRUAL CYCLE*

Abstract

Changes in the day-to-day excretion of ICSH have been determined qualitatively throughout 17 menstrual cycles in 13 normal adult women by means of a technique which depends upon the repair of ventral prostatic atrophy in in the hypophysectomized immature male rat. Changes in the excretion of FSH were estimated from the concomitant changes in testicular weight. Composite curves were derived by summating the average deviations from the mean of each individual cycle according to: (a) the days of the cycle, (b) the days preceding or following the clay of minimum basal body temperature, and (c) the days prior to the next menstrual period. The quantitative relations between the day-to-day variations in the weights of the ventral prostate and testis were examined by computing regression equations, expressing the composite change in prostatic weight per unit change in testicular weight. It is concluded that the normal menstrual cycle is characterized by: I) A midcycle peak period of FSH and ICSH excretion, during the early phase of which there is a change in the ratio of ICSH to FSH and a transient preponderance of ICSH. The onset of the mid-cycle peak is closely related in time to the shift in basal body temperature. 2) A late luteal trough followed by a rising trend in the excretion of both hormones, beginning toward the end of the luteal phase and continuing into menstruation.