The effect of two alkylphenols on vitellogenin levels in male carp

Nonylphenol and octylphenol, the major biodegradation products of nonionic surfactants, are among the increasing number of widely used industrial chemicals that are recognized as endocrine disrupters. In this study, nonylphenol and octylphenol were administered to male carp by injection, feeding and immersion, and a validated enzyme-linked immunosorbent assay (ELISA) was used to monitor the plasma levels of the yolk precursor vitellogenin over time. In injection and feeding experiments, vitellogenin levels increased significantly after 14 days. After immersion for 14 and 28 days, respectively, significantly higher concentrations of plasma vitellogenin were detected in male carp exposed to 4 microg/L nonylphenol and octylphenol. When transferred to clean water, the elevated plasma vitellogenin levels in carp exposed to 4 microg/L octylphenol for 42 days returned to control levels within 28 days.