Thyroxine and triiodothyronine uptake by the brain of chickens.
The instant uptake of 125-I-labelled triiodothyronine and 125-I-thyroxine by the brain tissue was measured in sham-operated (SH) controls, thyroidectomized (TX) and thyroidectomized plus iodothyronine supplemented (TX+T3 or TX+T4) young chickens. It was found that thyroidectomy significantly increases the uptake of iodothyronines, and iodothyronine supplementation returns the uptake close to sham-operated levels. The characteristics of the inhibition of the uptake of labelled hormones by non-labelled iodothyronines speak in favour of the presence of specific, separate uptake sites for T3 and T4 in the blood-brain barrier of young chickens.
Department of Physiology and Biochemistry, University of Veterinary Science, Budapest, Hungary.
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Rudas
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Bartha
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000378:metabolism*; D002645:Chickens; D013965:Thyroidectomy; D013974:Thyroxine / Q000493:pharmacokinetics* / Q000494:pharmacology; D014284:Triiodothyronine / Q000493:pharmacokinetics* / Q000494:pharmacology
D014284:Triiodothyronine; D013974:Thyroxine