title: Effects of butachlor on reproduction and hormone levels in adult zebrafish (Danio rerio).
abstract: Butachlor, a chloracetamide herbicide, is widely used in China. In the present study, paired adult male and female zebrafish (Danio rerio) were exposed to various concentrations of butachlor (0, 25, 50 and 100 μg/L) for 30 days, and the effects on reproduction and endocrine disruption were evaluated using fecundity, condition factor (CF), gonadosomatic index (GSI), liver somatic index (LSI), plasma vitellogenin (VTG), sex steroids and thyroid hormone levels as endpoints. Our results showed that the mean fecundity rates were significantly decreased at 50 and 100 μg/L butachlor during the 30-day exposure period. At the end of the exposure period, no significant changes were observed in CF and LSI in both females and males, while GSI was significantly reduced in males at 50 and 100 μg/L butachlor. At 100 μg/L butachlor, plasma testosterone (T) and 17β-estradiol (E2) levels were significantly decreased in females, while plasma VTG level was significantly increased in males. Plasma thyroxine (T4) and triiodothyronine (T3) levels were significantly increased at 50 and 100 μg/L butachlor in males, and at 100 μg/L in females. This work demonstrated that butachlor adversely affected the normal reproductive success of zebrafish, and disrupted the thyroid and sex steroid endocrine systems, which provides the basis for the estimated ecological risk during butachlor exposure.
authors.affiliation: Department of Pesticide Science, College of Plant Protection, Nanjing Agricultural University, Key Laboratory of Monitoring and Management of Crop Diseases and Pest Insects, Ministry of Agriculture, Nanjing 210095, China.
authors.forename: Juhua
authors.initials: J
authors.lastname: Chang
authors.forename: Shaoying
authors.initials: S
authors.lastname: Liu
authors.forename: Shengli
authors.initials: S
authors.lastname: Zhou
authors.forename: Minghua
authors.initials: M
authors.lastname: Wang
authors.forename: Guonian
authors.initials: G
authors.lastname: Zhu
mesh_terms: D000083:Acetanilides / Q000633:toxicity*; D000818:Animals; D004305:Dose-Response Relationship, Drug; D052244:Endocrine Disruptors / Q000633:toxicity*; D005260:Female; D005298:Fertility / Q000187:drug effects*; D012739:Gonadal Steroid Hormones / Q000097:blood*; D008297:Male; D013963:Thyroid Hormones / Q000097:blood*; D013997:Time Factors; D014819:Vitellogenins / Q000097:blood; D015027:Zebrafish / Q000097:blood / Q000502:physiology
chemical_list: D000083:Acetanilides; D052244:Endocrine Disruptors; D012739:Gonadal Steroid Hormones; D013963:Thyroid Hormones; D014819:Vitellogenins; C054409:butachlor