Effects of 17Îø-estradiol, 4-nonylphenol, and Îø-sitosterol on the growth hormone-insulin-like growth factor system and seawater adaptation of rainbow trout (Oncorhynchus mykiss) [electronic resource]

Previous studies show that successful adaptation of euryhaline teleost fish to seawater (SW) involves the GH-IGF system. The increasing occurrence, distribution, and concentration of environmental contaminants, including environmental estrogens (EE), in aquatic habit over recent time may compromise the hypoosmoreegulatory ability of fish. In this study, we used rainbow trout (Oncorhynchus mykiss) to assess the effects of EE on the GH-IGF system and adaptation to increased salinity. Juvenile trout (ca. 30g) were exposed to either low (10Îơg/l) or high (100Îơg/l) concentrations of Îø-sitosterol, 4-n-nonylphenol (NP), or 17Îø-estradiol (E2) for 28days in fresh water (FW); after which, fish were exposed to 20‒ SW. Plasma chloride levels in control fish rose initially, and then declined to initial levels after 48h. By contrast, plasma chloride levels in all EE-treated groups except Îø-sitosterol low increased and remained elevated over initial levels after 48h. Levels GH receptor 1 (GHR