Abstract
To clarify the origin of estrogens in infant blood, we measured E1 and E2 in the gonads of 50 girls and 64 boys deceased by sudden death between birth and 2 years of age. In both sexes, E2 was the major gonadal estrogen which exceeded E1 almost tenfold in the ovaries and twice in the testes. Thus, there was a clear sex difference in gonadal estrogen concentrations. On an average, girls had 8 times higher E2 and twice as high E1 concentrations in their gonads than boys. As in plasma, E2 concentrations were highest in ovaries of 2 to 4 months old girls (2 - 55 ng/g) and in testes of 1 to 3 months old boys (0.6 - 6.4 ng/g). Ovarian E2 concentrations decreased to values below 3 ng/g until the end of the 1st year of life, testicular E2 reached values below I ng/g already by 6 months of age. The gonadal steroidogenic activity paralleled changes in gonadal morphology. Ovarian weights showed a similar pattern of rise and fall as the E2 concentrations, the biggest ovaries consisting of multiple macroscopic cysts. In boys, testicular E2 closely correlated with Leydig cell development and testicular testosterone concentrations. We conclude that the surge of E2 in the blood of infant girls and boys originates from ovarian follicles and testicular Leydig cells, respectively, which develop under the influence of the characteristic post-natal gonadotropin surge.
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Bidlingmaier, F., Strom, T., Dörr, H. et al. SEX DIFFERENCES IN GONADAL ESTRADIOL (E2) AND ESTRONE (E1) CONCENTRATIONS IN INFANCY. Pediatr Res 20, 1178 (1986). https://doi.org/10.1203/00006450-198611000-00030
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DOI: https://doi.org/10.1203/00006450-198611000-00030