Application of metamorphosis assay to a native Japanese amphibian species, Rana rugosa, for assessing effects of thyroid system affecting chemicals.
The aims of this study were to assess the utility of a metamorphosis assay for detecting thyroid hormone-disrupting chemicals using Rana rugosa, a domestic frog species in Japan, and to compare species differences in sensitivity to thyroxine (T(4)) and propylthiouracil (PTU) among R. rugosa, Xenopus laevis and Xenopus (Silurana) tropicalis. Tadpoles of R. rugosa (TK stages III/IV) were exposed to standard test chemicals for acceleration (T(4)) and inhibition (PTU) of metamorphosis for 28 days in semi-static condition and total body length and developmental stage (TK stage) were recorded every week. T(4) (0.61 and 2.24 microg/L in actual concentrations) and PTU (19.73, 76.83, and 155.67 mg/L in actual concentrations) induced significant acceleration and inhibition of metamorphosis, respectively. The present results indicate that the metamorphosis assay is successfully applied to the domestic frog species, R. rugosa, suggesting this assay can be used for the assessment of chemicals on ecological impacts in wild frog species.
Oka
Tomohiro
T
Institute of Environmental Ecology, IDEA Consultants, Inc, Yaizu, Shizuoka, Japan.
Miyahara
Maki
M
Yamamoto
Jun
J
Mitsui
Naoko
N
Fujii
Takaaki
T
Tooi
Osamu
O
Kashiwagi
Keiko
K
Takase
Minoru
M
Kashiwagi
Akihiko
A
Iguchi
Taisen
T
D000818:Animals; D013956:Antithyroid Agents / Q000633:toxicity*; D001681:Biological Assay; D004305:Dose-Response Relationship, Drug; D052244:Endocrine Disruptors / Q000633:toxicity*; D005240:Feasibility Studies; D005260:Female; D007814:Larva / Q000187:drug effects; D008297:Male; D008675:Metamorphosis, Biological / Q000187:drug effects*; D011441:Propylthiouracil / Q000633:toxicity; D011898:Ranidae / Q000196:embryology / Q000254:growth & development*; D013045:Species Specificity; D013696:Temperature; D013961:Thyroid Gland / Q000187:drug effects*; D013974:Thyroxine / Q000633:toxicity; D013997:Time Factors; D046509:Tissue Culture Techniques; D018675:Toxicity Tests / Q000379:methods*; D014982:Xenopus laevis / Q000254:growth & development
D013956:Antithyroid Agents; D052244:Endocrine Disruptors; D011441:Propylthiouracil; D013974:Thyroxine