文献类型：会议论文

英文题名：Low-dose effects on thyroid disruption in zebrafish by long-term exposure to oxytetracycline

作者：Yu, Kan[1,2];Li, Xiaoyong[3];Qiu, Yushu[2];Zeng, Xinxin[2];Yu, Xiaogang[4];Wang, Weiye[4];Yi, Xiaoping[1];Huang, Lisu[2]

机构：[1]East China Univ Sci & Technol, State Key Lab Bioreactor Engn, Shanghai 200237, Peoples R China;[2]Shanghai Jiao Tong Univ, Xinhua Hosp, Sch Med, Dept Pediat, Shanghai, Peoples R China;[3]Shanghai Jiao Tong Univ, Xinhua Hosp, Sch Med, Shanghai, Peoples R China;[4]Shanghai Jiao Tong Univ, Xinhua Hosp, Sch Med, Municipal Key Lab Environm & Childrens Hlth, Shanghai, Peoples R China

会议论文集：20th International Symposium on Pollutant Responses in Marine Organisms (PRIMO)

会议日期：MAY 19-22, 2019

会议地点：Charleston, SC

语种：英文

外文关键词：Antibiotic exposure; Developmental toxicity; Thyroid disruption; Oxytetracycline in the aquatic environment

摘要：As a feed additive in agriculture, the antibiotic oxytetracycline (OTC) has become widely distributed in the natural environment, leading to the exposure of many organisms to low doses of OTC. Although OTC is clinically contraindicated in children because of its multiple side effects, the effect of exposure to low doses of environmental OTC on children is unknown, particularly during development. In this study, we investigated the effects of OTC on the thyroid endocrine system in zebrafish, through determinations of the whole-body contents of triiodothyronine (T3), thyroxine (T4), and thyroid-stimulating hormone (TSH) by enzyme-linked immunosorbent assay, and analysis of the mRNA expression of regulatory genes involved in the hypothalamus-pituitary-thyroid (HPT) axis using quantitative real-time polymerase chain reaction. Zebrafish embryos were exposed to OTC at environmentally relevant concentrations from 2 h to 120 days post-fertilisation. After exposure to OTC at 1,000 and 5,000 ng/L, T3 contents were significantly enhanced (37.8% and 45.1%, respectively) and TSH contents were reduced (16% and 16.3%, respectively) compared with those in the controls. The OTC-driven increase in the transcription of genes involved in thyroid synthesis (tpo and nis) may be responsible for the altered T3 levels. These data indicate that OTC may cause thyroid dysfunction and lead to reduced TSH secretion owing to enhanced negative feedback control of the HPT axis. Meanwhile, a decrease in body length, weight, and BMI and an increase in heart rate were observed with increasing OTC exposure. In conclusion, our results indicate that long-term exposure to low concentrations of OTC may alter the transcription of key genes involved in the HPT axis, as well as T3 and TSH contents, thereby disrupting the thyroid system and affecting the growth and development of zebrafish.