Alterations in Brain Norepinephrine and Serotonin Metabolism Following Experimental Hypothyroidism Induced by Methimazole

1974; Marcel Dekker; Volume: 1; Issue: 3 Linguagem: Inglês

10.3109/07435807409088992

ISSN

0093-6391

Autores

R.B. Rastogi, Radhey L. Singhal,

Tópico(s)

Thyroid Disorders and Treatments

Resumo

AbstractTreatment of neonatal rats with methimazole for 30 days resulted in typical signs of cretinism and produced significant reduction in the levels of brain norepinephrine and serotonin as well as in the activities of tyrosine hydroxylase and tryptophan hydroxylase. In contrast, the concentration of brain 5-hydroxy-indoleacetic acid was increased in rats given methimazole. Whereas administration of 25 μg/100 g dose of L-triiodothyronine for 3 days failed to restore the observed neurochemical changes, 250 μg/100 g dose of the hormone produced significant increases in brain nor-epinephrine and serotonin as well as elevated the activities of the two hydroxylase enzymes involved in the synthesis of these putative neurotransmitters. Our results suggest that methimazole impairs the metabolism of brain norepinephrine and serotonin and that the depressed behaviour seen during cretinoid state may be related to diminished interactions of these monoamines at postsynaptic sites.

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