title: Active transport of L-tri-iodothyronine through the red cell plasma membrane--true or false?
abstract: The membrane transport of L-tri-iodothyronine has been studied in human erythrocyte ghosts. Initial uptake showed saturability with a Km of 33.8 nmol/l, suggesting carrier-mediated transport. Ouabain partly inhibited this uptake. ATP, on the other hand, caused a significant increase in the Vmax indicating an active transport of L-tri-iodothyronine across the erythrocyte plasma membrane. Ghosts from patients with hyperthyroidism, hypothyroidism or thyroid hormone resistance did not differ significantly from controls in their uptake of the hormone.
mesh_terms: D000255:Adenosine Triphosphate / Q000097:blood / Q000494:pharmacology; D002463:Cell Membrane Permeability; D004912:Erythrocytes / Q000378:metabolism*; D006801:Humans; D010042:Ouabain / Q000494:pharmacology; D013959:Thyroid Diseases / Q000097:blood; D014284:Triiodothyronine / Q000097:blood*
chemical_list: D014284:Triiodothyronine; D010042:Ouabain; D000255:Adenosine Triphosphate