쥐노래미, Hexagrammos otakii의 난소 내 성 스테로이드 활성에 미치는 nonylphenol과 bisphenol A의 에스트로젠 효과

Abstract

In this study, vitellogenic (oocyte diameter of 0.70-0.74, 0.82-0.86 and 1.08-1.12 mm) and mature oocytes (oocyte diameter of 1.95-1.97 mm) from the greenling (Hexagrammos otakii) were exposed to in vitro xenoestrogens such as nonylphenol (NP) and bisphenol A (BPA). To investigate the effect of NP on steroid metabolism, vitellogenic oocytes were incubated with 10 ng/ml of NP in the presence of [3H]17α-hydroxyprogesterone as precursor. The major metabolites produced in vitro are androgens [androstenedione (A4) and testosterone (T)] and estrogens [estrone (E1) and estradiol-17β (E2)]. NP showed no clear effects on steroid metabolism at vitellogenic oocytes. In the effect of NP on steroid production at vitellogenic stage, NP increased E2/T ratio at 0.1, 1 and 10 ng/mL in the oocytes of 0.80-0.82 and 0.92-0.96 mm. In the oocytes of 1.08-1.12 mm, NP increased E2/T ratio only at 100 ng/mL. Oocytes of 1.95-1.97 mm were exposed to NP and BPA with or without 50 IU HCG (human chorionic gonadotropin). NP increased E2/T ratio at 0.1, 10 and 100 ng/mL without HCG and increased E2/T ratio only at 100 ng/mL with HCG. Moreover, NP inhibited 17α20βOHP production at every concentration without HCG. In BPA treatment, BPA increased E2/T ratio at 0.1, 1 and 100 ng/mL regardless HCG. BPA inhibited 17α20βOHP production only at 100 ng/mL without HCG although BPA stimulated 17α20βOHP production at 1 ng/mL with HCG. Taken toghther, these results suggest that NP exhibited clearly estrogenic activity regardless ovarian development and BPA has weak estrogenic potency at final oocyte maturation stage of H. otakii.