Endocrine disruption by di-(2-ethylhexyl)-phthalate in Chinese rare minnow (Gobiocypris rarus)

• Published in: Environmental toxicology and chemistry 2013-08, Vol.32 (8), p.1846-1854
• Main Authors: Wang, Xiaofang, Yang, Yuanjin, Zhang, Liping, Ma, Yanbo, Han, Jian, Yang, Lihua, Zhou, Bingsheng
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; China; Chinese rare minnow; Cyprinidae - physiology; Di-(2-ethylhexyl)-phthalate (DEHP); Diethylhexyl Phthalate - toxicity; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; Endangered Species; Endocrine disruption; Endocrine Disruptors - toxicity; Endocrine System - drug effects; Estradiol - metabolism; Exposure; Female; Females; Fish; Freshwater; Fundamental and applied biological sciences. Psychology; Genes; Gobiocypris rarus; Gonadal Steroid Hormones - metabolism; Gonads; Hypothalamic-pituitary-gonadal (HPG) axis; Liver; Liver - drug effects; Male; Males; Sex hormones; Testosterone - metabolism; Vitellogenins - metabolism; Water Pollutants, Chemical - toxicity
• ISSN: 0730-7268; 1552-8618
• DOI: 10.1002/etc.2261

Great concern has been raised over the potential impact of environmental contaminants on fish populations that inhabit the Three Gorge Reservoir. The present study investigated the endocrine‐disrupting effects of di‐(2‐ethylhexyl)‐phthalate (DEHP) on the Chinese rare minnow (Gobiocypris rarus), an endemic fish distributed in upstream waters in the Yangtze River. Adult rare minnow were exposed to environmentally relevant concentrations of DEHP (0 µg/L, 3.6 µg/L, 12.8 µg/L, 39.4 µg/L, and 117.6 µg/L) for a 21‐d period. Then, concentrations of sex hormones in the plasma and relative transcription of various associated genes were measured in the hypothalamic–pituitary–gonadal (HPG) axis and liver of the fish. Exposure to DEHP resulted in greater circulating concentrations of testosterone (T) and lower concentrations of estradiol (E2), which were accompanied by upregulation of Cyp17 mRNA and downregulation of Cyp19a mRNA in the gonads of females. In males, increases of T and E2 levels were consistent with upregulation of Cyp17 and Cyp19a in the gonads. Furthermore, the T/E2 ratio was increased in females but reduced in males. A significant increase in the levels of hepatic vitellogenin (VTG) gene transcription was observed in both females and males. The present study showed that waterborne exposure to DEHP altered plasma sex hormone levels and modulated gene transcription profiles of associated genes in the HPG axis and liver, occurring mostly at higher concentrations (>39.4 µg/L), which suggests that environmental concentration of DEHP (5.4 µg/L) alone might not disturb the endocrine system of the rare minnow in the TGR. Environ Toxicol Chem 2013;32:1846–1854. © 2013 SETAC