Effects of 4-nonylphenol on production of plasma vitellogenine and changes Steroid hormones in koi carp (Cyprinus carpio carpio)

Estrogenic effect of 4 - nonylphenol on plasma vitellogenin and sex steroid hormones (17 – β-estradiol ,testosterone and progesterone ) were studied in immature Koi carp . In order to, fish for over three weeks Received Intraperitoneal injection of 10 , 50 and 100 microgram per gram of 4 -nonylphenol and 2 microgram per gram of 17- β-estradiol per body weight . Fish samples were taken on days 0 and 22. The concentration of sex hormones in plasma measured by radioimmunoassay and Plasma vitellogenin levels were measured by ELISAThe results showed that amount of vitellogenin protein and estradiol hormne one at concentration 50 micrograms of 4- nonylphenol (51/66± 21/3) and 2 micrograms of 17 β-estradiol (58±6/02) in males and females increased significantly compared with the control group(P <0.05).But the changes in vitellogenin and 17- β-estradiol at a concentration of 100 micrograms nonylphenol showed significantly reduced compared with concentrations of 10 and 50 micrograms of nonylphenol (P <0.05). In the case of progesterone in all the groups that were treated with nonylphenol ,the effect was not showed statistically significant,and only at concentrations of 2 micrograms 17-β-estradiol showed significant decrease(P> 0.05),Also testosterone levels,except in group 2 microgram 17-β-estradiol treated group had no significan difference(P >0.05). These results indicate harmful effects of 4- nonylphenol using hormonal markers and assess the susceptibility of immature Koi Carp are against these compounds .