Thyroidal Hormone Disrupting Effects and Histopathological Examination in an Amphibian Metamorphosis Assay
نویسنده
چکیده
ment (OECD) and the US Environmental Protection Agency (EPA) have focused on thyroid toxicity and have formulated guidelines for detailed investigations of the process of metamorphosis in African clawed frogs (Xenopus laevis, Fig. 1).1), 2) The thyroid gland, which is in the heads of tadpoles and which is the target of histological examinations in toxicity studies, is on a line between the two eyes (Fig. 2). Because the tissue is extremely small at the beginning of metamorphosis and because the shape of the head changes as metamorphosis progresses, with the position of the thyroid gland changing with it, there is a difference from normal mammals. It is been found that accumulating know-how for pathological studies is necessary for accurate evaluations of toxicity. From the point of view described above and in consideration of the most recent trends in regulations in Thyroidal Hormone Disrupting Effects and Histopathological Examination in an Amphibian Metamorphosis Assay
منابع مشابه
Thyroid Hormone-disrupting Effects and the Amphibian Metamorphosis Assay
There are continued concerns about endocrine-disrupting chemical effects, and appropriate vertebrate models for assessment of risk are a high priority. Frog tadpoles are very sensitive to environmental substances because of their habitat and the complex processes of metamorphosis regulated by the endocrine system, mainly thyroid hormones. During metamorphosis, marked alteration in hormonal fact...
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