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PubMed · 8663353

Thyroid hormone export regulates cellular hormone content and response.

R C Ribeiro·R R Cavalieri·N Lomri·C M Rahmaoui·J D Baxter·B F Scharschmidt
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Abstract

Actions of thyroid hormones (THs) are determined by intracellular free hormone concentration. Here we report that enhanced TH extrusion via a saturable, cold-sensitive mechanism lowers intracellular TH and causes TH resistance in hepatoma cells. Since these cells overexpress multidrug resistance P-glycoproteins and TH extrusion and resistance are blunted by verapamil, P-glycoproteins may mediate this resistance. Verapamil-inhibitable TH efflux was also found in primary hepatocytes, cardiocytes, and fibroblasts. These findings demonstrate that TH extrusion can modulate TH availability and action in mammalian cells.

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ATP Binding Cassette Transporter, Subfamily B, Member 1AnimalsAnimals, NewbornBase SequenceCell LineCells, CulturedEstradiolHeartHeart VentriclesHumansLiverLiver Neoplasms, ExperimentalMolecular Sequence DataMyocardiumRatsReceptors, Thyroid HormoneRecombinant ProteinsThyroxineTransfectionTriiodothyronineTumor Cells, CulturedVerapamilVitellogeninsJournal ArticleResearch Support, Non-U.S. Gov'tResearch Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

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R C Ribeiro, R R Cavalieri, N Lomri, C M Rahmaoui, J D Baxter, B F Scharschmidt. 1996-07-19. Thyroid hormone export regulates cellular hormone content and response.. https://doi.org/10.1074/jbc.271.29.17147

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