Schubert Sara, Peter Armin, Burki Richard, Schönenberger René, Suter Marc J-F, Segner Helmut, Burkhardt-Holm Patricia
Eawag - Swiss Federal Institute of Aquatic Science and Technology, 6047 Kastanienbaum, Switzerland.
Aquat Toxicol. 2008 Oct 20;90(1):65-72. doi: 10.1016/j.aquatox.2008.08.002. Epub 2008 Aug 12.
A decline in brown trout (Salmo trutta fario) catches has been reported in Switzerland, but at present the causative factors have not been clearly identified. Estrogen-active endocrine disrupters (EEDs) have been suggested as one possible explanation, since they are widespread in the aquatic environment and often found at elevated concentrations. In the present study the effects of long-term estrogenic exposure on the reproductive capability of brown trout were investigated. Adult fish were continuously exposed to an environmentally relevant mixture of the natural estrogens estrone (E1), 17beta-estradiol (E2) and the xenoestrogen 4-nonylphenol (NP); the average measured concentrations over the entire exposure time (n=9) were 14.0 ng/l (Min 8.1 and Max 20.6) for E1, 2.1 ng/l (Min 1.3 and Max 4.1) for E2 and 111.0 ng/l (Min 106.7 and Max 115.9) for NP. A solvent control served as negative control, and up to 10-fold higher mixture concentration than the environmentally relevant concentration served as positive control. The fish were exposed for 150 days from the onset of gonadal recrudescence until sexual maturation. Plasma vitellogenin (Vtg) was significantly induced by both concentrations of the estrogenic mixture, whereas effects on growth and fertility were only observed in fish exposed to the high mixture treatment. Fertilization success and offspring hatchability in brown trout exposed to the high mixture treatment were significantly reduced to 9% and 6%, respectively. Developmental time from fertilization until hatching, the percentage of larvae with malformations and survival of larvae, however, were not affected. The results suggest that a combination of estrogen-active compounds at environmentally relevant concentrations would not adversely affect those parameters of brown trout reproductive capability measured in this study. Plasma Vtg in male brown trout appeared to be more sensitive to (xeno)estrogen exposure than the measured reproductive effects.
瑞士曾有报道称褐鳟（Salmo trutta fario）的捕获量有所下降，但目前尚未明确其致病因素。有人提出具有雌激素活性的内分泌干扰物（EEDs）可能是一个原因，因为它们在水生环境中广泛存在，且经常以较高浓度被发现。在本研究中，调查了长期雌激素暴露对褐鳟繁殖能力的影响。成年鱼持续暴露于天然雌激素雌酮（E1）、17β - 雌二醇（E2）和外源性雌激素4 - 壬基酚（NP）的环境相关混合物中；整个暴露期（n = 9）内测得的平均浓度分别为：E1为14.0 ng/l（最小值8.1，最大值20.6），E2为2.1 ng/l（最小值1.3，最大值4.1），NP为111.0 ng/l（最小值106.7，最大值115.9）。以溶剂对照作为阴性对照，比环境相关浓度高10倍的混合物浓度作为阳性对照。从性腺再发育开始到性成熟，鱼被暴露150天。两种浓度的雌激素混合物均显著诱导血浆卵黄蛋白原（Vtg），而对生长和繁殖力的影响仅在暴露于高浓度混合物处理的鱼中观察到。暴露于高浓度混合物处理的褐鳟的受精成功率和后代孵化率分别显著降低至9%和6%。然而，从受精到孵化的发育时间、畸形幼虫的百分比以及幼虫的存活率均未受影响。结果表明，环境相关浓度的具有雌激素活性的化合物组合不会对本研究中所测量的褐鳟繁殖能力参数产生不利影响。雄性褐鳟的血浆Vtg对外源性雌激素暴露似乎比所测量的繁殖效应更敏感。
