| Abstract: | Plasma levels of 2-hydroxyestrone (2-OHE1) were measured by specific radioimmunoassay during puberty to elucidate the physiological role of this hormone on female sexual development. Plasma levels of FSH, LH, PRL and estradiol (E2) were also measured with an RI-kit. 67 girls between aged 6 and 16 were selected for this study. Blood samples were collected into tubes containing 0.1W/V% EDTA and 0.1W/V% ascorbic acid and immediately centrifuged. 2-OHE1 in plasma was extracted and separated with a Sephadex LH-20 column. RIA was applied using anti 2-OHE1-17-CMO-BSA. Plasma 2-OHE1 levels before menarche were low (6-7 pg/ml) until 10 years of age. The levels started to increase from 11 and reached 11.2 +/- 5.8pg/ml at 16 years of age. The levels of 2-OHE1 in girls after menarche were significantly higher than that before menarche (p less than 0.01). There was a significant correlation between 2-OHE1 and E2 in girls before menarche (p less than 0.001, r = 0.5416). However, the 2-OHE1 to E2 ratio decreased significantly from 9 to 10 years of age. These results indicate that during this period, the E2 increase is more predominant than that of 2-OHE1. There was a significant negative correlation between 2-OHE1 and PRL after menarche while no correlation between 2-OHE1 and FSH, LH was noticed. These results suggested that 2-OHE1 may play a role in sexual development after menarche rather than in the initiation of menarche. |
