抄録
Nonylphenol has been detected in the aquatic environment in Japan, and a concern has arisen over its ability to interact with and potentially disrupt vertebrate endocrine systems. To establish a model system to estimate the effects of endocrine disrupting chemicals on aquatic animals, we evaluated the effects of p-nonylphenol(NP) on the early life stage of the mummichog (Fundulus heteroclitus). Mummichog fertilized eggs were exposed to seawater containing NP at 146, 24.2, or 9.1 µg/L until 10 weeks after hatching. In fry treated with 146 NPµg/L, survival rates decreased to 26 %, and 15 % of all fry showed malformations. Vitellogenin (Vg) concentrations were determined by time-resolved fluoroimmunoassay with rabbit antibody against mummichog Vg. Vg was detected in the abdominal fluid of all fry exposed to NP, and a dose-dependent response relationship was observed between concentrations of Vg and concentrations of NP. Our results suggest that mummichog is sensitive to NP and can synthesize Vg in the early life stage. Thus Vg in the abdominal fluid of fry is a sensitive biomarker of endocrine disruption. Young mummichog can be used as a sensitive in vivo testing system for estrogenic chemicals.
