Thyroid iodide transport is reduced by administration of monoamine oxidase A inhibitors to rats
| Autor: | Claudia Gabriela Pellizas, Maria Eugenia Costamagna, Ana María Masini-Repiso, Ana M. Cabanillas, A. H. Coleoni |
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| Rok vydání: | 1994 |
| Předmět: |
Male
Clorgyline medicine.medical_specialty Monoamine Oxidase Inhibitors Monoamine oxidase Endocrinology Diabetes and Metabolism Thyroid Gland chemistry.chemical_element Iodine Organ Culture Techniques Endocrinology Internal medicine Selegiline medicine Animals Iodide transport Rats Wistar Monoamine Oxidase biology Chemistry Tranylcypromine Thyroid Biological Transport Iodides Pargyline Rats medicine.anatomical_structure Enzyme inhibitor biology.protein medicine.drug |
| Zdroj: | Journal of Endocrinology. 143:303-308 |
| ISSN: | 1479-6805 0022-0795 |
| Popis: | The present work was addressed to study a possible relationship between monoamine oxidase (MAO) and the thyroid iodide transport mechanism. Normal rats treated with clorgyline (a selective MAO-A inhibitor) or tranylcypromine (a non-selective MAO inhibitor) showed a significantly diminished thyroid MAO activity, while deprenyl and pargyline (MAO-B inhibitors) did not modify the thyroidal enzyme activity with respect to the control group. Under these conditions, in vivo iodide transport was reduced both by clorgyline and tranylcypromine administration whereas it remained unchanged after treatment with MAO-B inhibitors. The effect of MAO inhibitors on thyroid MAO activity and in vivo iodide transport was also evaluated in rats treated with exogenous thyrotrophin (TSH) after endogenous TSH secretion blockade produced by T4 administration. In this condition, thyroid MAO activity was significantly lowered by clorgyline and was not modified by deprenyl. In contrast to the results observed in normal rats, in vivo iodide transport in TSH-treated rats remained unaltered after treatment either with clorgyline or deprenyl. MAO activity evaluated in bovine thyroid follicles in primary culture was highly sensitive to low concentrations of clorgyline ( These results indicate the absence of a direct linkage between thyroid MAO activity and the active iodide transport. MAO inhibitors (particularly MAO-A inhibitors) do not appear to be responsible for an in vivo diminished thyroid iodide uptake through a direct action on the iodide transport mechanism. An indirect effect of MAO-A inhibitors on thyroid iodide transport mediated by the accumulation of monoamines in neuroendocrine areas involved in TSH regulation is suggested. Journal of Endocrinology (1994) 143, 303–308 |
| Databáze: | OpenAIRE |
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