URINARY-EXCRETION OF ESTRONE GLUCOSIDURONATE, 17BETA-ESTRADIOL-17-GLUCOSIDURONATE, AND ESTRIOL-16ALPHA-GLUCOSIDURONATE - SIGNIFICANCE OF PROPORTIONATE DIFFERENCES DURING THE MENSTRUAL-CYCLE

The urinary excretion of estrone glucosiduronate, 17β-estradiol-17-glucosiduronate, and estriol-16α-g1ucosiduronate in men and throughout the menstrual cycle in women was measured by specific radioimnunoassay. In 9 men the mean ± SE excretion of these conjugates was 15.9 ± 1.4, 2.7 ± 0.3, and 3.2 ± 0.2 μg/24 h respectively. In 15 women studied in the midfollicular phase (day 8) of the menstrual cycle, the excretion was 19.4 ± 1.7, 2.9 ± 0.2, and 5.4 ± 1.3 μg/24 h. Excretion of each conjugate was significantly (P<0.01) elevated in the midluteal phase (day 22) to 41.9 ± 3.9, 6.3 ± 0.8, and 12.2 ± 1.5 μg/24 h respectively (n = 14). The mean excretion of estriol-16α-g1ucosiduronate was greater than that of 173-estradiol-17-g1ucosiduronate in the luteal phase (P<0.05) but not in the follicular phase or in men (P>0.05). The excretion of each of these specific conjugates measured throughout the menstrual cycle in 7 women was characterized by a sharp midcycle peak and a lower, broader luteal phase peak. The ratios of estriol-16α-g1ucosiduronate to 17β-estradiol-17-glucosiduronate, estrone glucosiduronate to 17β-estradiol-17-glucosiduronate, and estriol-16α-g1ucosiduronate to estrone glucosiduronate throughout the menstrual cycle were analyzed. When the mean ratio during the follicular phase was set at 1, a significant increase (P<0.01) occurred in the mean luteal phase ratio in each case: 1.00 ± 0.03 to 1.66 ± 0.09, 1.00 ± 0.04 to 1.30 ± 0.04, and 1.00 ± 0.03 to 1.24 ± 0.04 (mean ± SE) respectively. The marked alteration in the proportions of these urinary estrogen conjugates may be due to altered metabolism of 17β-estradio1, but it more likely reflects a change in the pattern of estrogen secretion or production between the two phases of the menstrual cycle. © 1979.