Effects of cadmium, 17β-estradiol and their interaction in the male Chinese loach (Misgurnus anguillicaudatus)

To assess the interaction effect between cadmium (Cd) and 17β-estradiol (E2), male Chinese loaches (Misgurnus anguillicaudatus) were exposed to E2 (1 μg/L) and Cd (50 or 500 μg/L) alone and in combination using a semi-static waterborne exposure system. The effects of E2 on the accumulation and distribution of Cd, as well as the effects of Cd on vitellogenin (Vtg) synthesis induced by E2, were investigated. Cd mainly accumulated in the kidneys, liver, intestines, and gills, with little amounts in muscles, bones, and gonads. Co-exposure with E2 did not change the main targets for Cd. E2 could induce Vtg synthesis in male Chinese loaches, and co-exposure with 50 or 500 μg/L Cd could inhibit the Vtg induced by 1 μg/L E2. Compared with the results reported in the literature, it can be concluded that factors such as fish species, Cd dosage, and manner of exposure might make contributions to the interaction between Cd and E2. Our results also suggested that male Chinese loaches are susceptible to Cd, and can be recommended as a potential sentinel species to study the ecotoxicology of heavy metals.