h i g h l i g h t s
Nitrate caused mortality increase in Bufo gargarizans larvae.
Nitrate could delay metamorphosis and increase body size.
Nitrate decrease thyroid hormone contents in Bufo gargarizans tadpole.
Nitrate caused partial colloid depletion in the thyroid gland follicles.
Nitrate induced down-regulation of Dio2 mRNA and up-regulation of Dio3 mRNA.