Mackenzie Constanze A, Berrill Michael, Metcalfe Chris, Pauli Bruce D
Watershed Ecosystems Graduate Program, Trent University, Peterborough, Ontario, K9J 7B8, Canada.
Environ Toxicol Chem. 2003 Oct;22(10):2466-75. doi: 10.1897/02-173.
Exposure of amphibians to endocrine disrupting compounds (EDCs) may alter differentiation of gonads, especially when exposures begin during early life stages. Gonadal differentiation was observed in leopard frogs (Rana pipiens) and wood frogs (Rana sylvatica) exposed as tadpoles to estrogenic (estradiol, ethinylestradiol, nonylphenol) and antiestrogenic compounds (an aromatase inhibitor, flavone, and an antiestrogen, ICI 182780). Exposure to all compounds at micrograms/L concentrations altered gonadal differentiation in some animals by inducing either complete feminization or an intersex condition, and altered testicular tubule morphology, increased germ cell maturation (vitellogenesis), and oocyte atresia. Comparisons between the two species indicate that R. pipiens are more susceptible to sex reversal and development of intersex gonads. However, R. sylvatica also showed alterations to testicular morphology, germ cell maturation, and ooctye atresia. These laboratory results indicate that amphibians could be susceptible to altered gonadal differentiation and development when exposed to estrogenic and antiestrogenic compounds in aquatic environments, such as those impacted by agricultural, industrial, and municipal runoff.
两栖动物接触内分泌干扰化合物（EDCs）可能会改变性腺分化，尤其是在生命早期阶段开始接触时。在豹蛙（Rana pipiens）和林蛙（Rana sylvatica）蝌蚪期接触雌激素（雌二醇、乙炔雌二醇、壬基酚）和抗雌激素化合物（一种芳香化酶抑制剂、黄酮和一种抗雌激素ICI 182780）时，观察到了性腺分化情况。以微克/升浓度接触所有化合物会在一些动物中通过诱导完全雌性化或雌雄同体状况改变性腺分化，并改变睾丸小管形态，增加生殖细胞成熟（卵黄生成）和卵母细胞闭锁。两种物种之间的比较表明，豹蛙对性逆转和雌雄同体性腺发育更敏感。然而，林蛙的睾丸形态、生殖细胞成熟和卵母细胞闭锁也出现了改变。这些实验室结果表明，当两栖动物在水生环境中接触雌激素和抗雌激素化合物时，如受到农业、工业和城市径流影响的环境，它们可能易发生性腺分化和发育改变。
