ESTROGEN METABOLISM IN THE HUMAN. III. A COMPARISON BETWEEN FEMALES, STUDIED DURING THE FIRST AND SECOND HALVES OF THE MENSTRUAL CYCLE, AND MALES

ABSTRACT Estrogen metabolism in females and males has been explored for possible differences between the sexes. Two female groups were studied, those in the first half (proliferative phase) of the menstrual cycle and those in the second half (secretory phase). These groups were compared with one another, and with a male group previously reported. Estradiol-17β,6,7-3H was administered, and the urinary excretion of radioactive estrone, estradiol-17β and estriol was determined, together with the simultaneous excretion of the corresponding endogenous (nonradioactive) estrogens. The interrelationship of radioactive and nonradioactive estrogens was studied by analysis of interaction. Specific activities and estradiol-17β production rates were calculated. Data for each group were fitted to a previously described mathematical model, designed to test the hypothesis that the 3 urinary estrogens are derived solely from estradiol-17β secreted into an inner pool. The interrelationship of the 3 radioactive estrogens wa...