Influence of temperature on growth, development and thyroid metabolism of American bullfrog tadpoles (Lithobates catesbeianus) exposed to the herbicide tebuthiuron

• Published in: Environmental toxicology and pharmacology 2022-08, Vol.94, p.103910-103910, Article 103910
• Main Authors: Grott, Suelen C., Israel, Nicole, Lima, Daína, Bitschinski, Daiane, Abel, Gustavo, Alves, Thiago C., da Silva, Elizia B., de Albuquerque, Claudia A.C., Mattos, Jacó J., Bainy, Afonso C.D., de Almeida, Eduardo A.
• Format: Article
• Language: English
• Subjects: Development; Tadpoles; Tebuthiuron; Temperature; Thyroid
• ISSN: 1382-6689; 1872-7077
• DOI: 10.1016/j.etap.2022.103910

The influence of temperature (25 and 32 °C) on the negative effects of the herbicide tebuthiuron (TBU, 0, 10, 50 and 200 ng.L-1, 16 days) on thyroid function and metamorphosis of Lithobates catesbeianus tadpoles was evaluated. Metamorphosis was accelerated by TBU exposure at 25 ºC, but delayed at 32 ºC with considerable losses of body mass. T3 and T4 levels were not altered. The highest TBU concentrarion at 25 ºC increased TR β and DIO3 transcript levels, which is consistent with development acceleration in tadpoles. At 32 ºC TR β transcript levels were lower than the values recorded at 25 ºC, and those tadpoles exposed to the highest TBU concentration presented increased diameter of thyroid follicles compared to controls at same temperature. This study evidences that TBU at environmentally realistic concentrations is able to disrupt thyroidogenesis in bullfrog tadpoles, impairing their development. These effects are influenced by temperature. [Display omitted] •Tebuthiuron (TBU) exposure at 25 °C accelerated tadpole development.•TBU exposure at 32 °C delayed tadpole development and caused weight loss.•TBU exposure at 32 °C increased the diameter of thyroid follicles.•Tadpoles kept at 32 °C presented lower TR β transcript levels.•Interactions of temperature and TBU affect thyroidogenesis impairing tadpole development.