The estrogenic effect of 4-nonylphenol on vitellogenin synthesis in the immature male yellowfin seabream, Acanthopagrus latus (Teleostei: Sparidae) (Houttuyn, 1782)

In the present study effects of estrogenic compound 4-nonylphenol was investigated on vitellogenin synthesis in the immature male yellowfin seabream (Acanthopagrus latus). The fish received intraperitoneal injections during a period of two weeks with 10، 50، 100، 150 and 200 µg g-1 week-1 of 4-nonylphenol. One of the treatments also injected with 2 µg g-1 week-1 of 17β-estradiol. Solvent controls received the ethanol-coconut oil only، whereas controls were not injected. The fish were sampled on day 0، 7 and 14. The induction of VTG in plasma of treated fish was determined indirectly by measuring the alkali-labile phosphate and total plasma calcium. Increased concentrations of these indicators indicated a dose–response induced synthesis of vitellogenin in the liver of the 4-nonylphenol-treated seabreams. Induction of vitellogenin synthesis also could be observed by increasing the hepatosomatic index (HSI) in the 4-nonylphenol-treated fish. The findings of this study showed the potency of nonylphenol to exert esterogenic effect as indicated by both increase in vitellogenin synthesis and HSI.