Effects of endocrine disruption by ۴-nonylphenol ethoxylate on the growth performance and immune response of female and male immature koi carp (Cyprinus carpio carpio)

Nonylphenol (NP) is an endocrine disrupting chemical which has been shown to be able tomodulate endocrine system of various organisms by different mechanisms. The objective of this study was to investigate the potential effects of ۴-NP and ۱۷-β - estradiol (E۲) on the immune parameters (IgM levels and lysozyme activity) of the teleost Koi carp (Cyprinus carpio carpio) for a better understanding of the immune-reproductive system interactions. The experimental fishes were injected with ascending doses (۱۰, ۵۰,۱۰۰ μgg-۱ body weight) of ۴- nonylphenol (۴-NP) and (۲ μgg-۱ body mass) of ۱۷-β-estradiol (E۲) or vehicle during ۳ weeks. After ۲۱ days, the fishes (۱۸۰) were anesthetizedand their blood samples were collected from caudal vein, then they were dissected and sexually separated by gonad characters. The measurement of immune parameters in plasma showed that ۴-NP induced significant increase in the IgM levels and lysozyme activity at dose of ۵۰ μgg-۱ while the levels of these parameters in the higher doses (۱۰۰ μgg-۱) decreased  compared with the control group (p<۰.۰۵). In addition the treatment, with ۲ μgg-۱ E۲ significantly decreased both the IgM levels and lysozyme activity after ۲۱ days of injection. These results indicated that ۴-NP and E۲ could lead to disturb the balance of immune system with  potential consequences for immature koi carp.

Keywords:

۴-nonylphenol , ۱۷-β-estradiol , Immune-reproductive system , Immunoglobulin IgM , Lysozyme , Koi carp (Cyprinus carpio carpio)