著者

Hideaki Tokusumi Naoto Fujioka Nguyen Minh Tue Akitoshi Goto Go Suzuki Kei Nakayama

出版者

The Japanese Society of Environmental Toxicology

雑誌

環境毒性学会誌 (ISSN:13440667)

巻号頁・発行日

vol.24, pp.1-11, 2021-01-15 (Released:2021-01-15)

参考文献数

27

---

In order to develop an optimal method for the investigation of relative potencies of dioxin-like compounds using Japanese medaka, the present study conducted five independent early-life stage toxicity tests using 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as the positive control. First, both short- and long-term effects of TCDD were examined to determine sensitive and highly reproducible endpoints. Then, the outcome and threshold of TCDD toxicities under different experimental conditions, e.g., exposure timing and duration, were compared to develop a cost-effective method. Finally, we decided to observe yolk sac/pericardial edema, hatching failure, and mortality of medaka embryos/larvae within a 28-d experimental period, after 6-h exposure to TCDD at 0-d post fertilization. We obtained the LC50 values of TCDD at 28-d post fertilization based on its concentration in water (6.84 ng/L) or in egg (753 pg/g-egg), and the LC50 values were comparable with those reported in the literature. Thus, in our future studies, relative toxic potencies of dioxin-like compounds will be tested using the method established in this study.