Journal article
Developmental neurotoxicity of Propylthiouracil (PTU) in rats: Relationship between transient hypothyroxinemia during development and long-lasting behavioural and functional changes
Markedly lowered thyroid hormone levels during development may influence a child's behaviour, intellect, and auditory function. Recent Studies, indicating that even small changes in the mother's thyroid hormone Status early in pregnancy may Cause adverse effects on her child, have lead to increased concern for thyroid hormone disrupting chemicals in the environment.
The overall aim of the Study was therefore to provide a detailed knowledge or) the relationship between thyroid hormone levels during development and long-lasting effects on behaviour and hearing. Groups of 16-17 pregnant rats (HanTac:WH) were dosed with PTU (0, 0.8.1.6 or 2.4 mg/kg/day) from gestation day (GD) 7 to postnatal day (PND) 17, and the physiological and behavioural development of rat offspring was assessed.
Both dams and Pups in the higher close groups had markedly decreased thyroxine (T-4) levels during the closing period, and the weight and histology of the thyroid glands were severely affected. PTU exposure caused motor activity levels to decrease on PND 14, and to increase on PND 23 and in adulthood.
In the adult offspring, learning and memory was impaired in the two highest dose groups When tested in the radial arm maze, and auditory function was impaired in the highest dose group. Generally, the results showed that PTU-induced hypothyroxinemia influenced the developing rat brain, and that all effects on behaviour and loss of hearing in the adult offspring were significantly correlated to reductions in T-4 during development.
This supports the hypothesis that decreased T-4 may be a relevant predictor for long-lasting developmental neurotoxicity. (C) 2008 Elsevier Inc. All rights reserved.
Language: | English |
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Year: | 2008 |
Pages: | 1-13 |
ISSN: | 10960333 and 0041008x |
Types: | Journal article |
DOI: | 10.1016/j.taap.2008.05.020 |
ORCIDs: | Petersen, Marta Axelstad , Boberg, Julie , Nellemann, Christine Lydia and Hass, Ulla |
Age Factors Animals Animals, Newborn Antithyroid Agents Auditory Threshold Behavior, Animal Behaviour Body Weight Developmental neurotoxicity Disease Models, Animal Dose-Response Relationship, Drug Female Gestational Age Hearing Hypothyroidism Male Maze Learning Motor Activity Nervous System Neurotoxicity Syndromes Organ Size PTU Pregnancy Prenatal Exposure Delayed Effects Propylthiouracil Rat Rats Rats, Wistar Thyroid Gland Thyroid hormone disrupting chemical Thyroxine