In vivo study of iodothyronine deiodination in rat liver: effect of salicylate on biliary excretion of several iodothyronines.
Biliary excretion of total (i.e. conjugated plus unconjugated) thyroxine (T4), 3,5,3'-triiodothyronine (T3), 3,3',5'-triiodothyronine (rT3), 3,5-diiodothyronine (3,5-T2), 3,3'-diiodothyronine (3,3'-T2) and 3',5'-diiodothyronine (3',5'-T2) was measured with the aid of specific radioimmunoassay in 17 control rats and in 31 rats injected sodium salicylate i.v. (200 mg kg-1). The animals were anesthetized with pentobarbiturate and the samples of bile were taken in subsequent 2 h periods from a drained bile duct. In controls a gradual decrease of excretion of all compounds measured was found during 10 h observation period. In contrast, after salicylate injection a transient increase of total bile volume and of T4, T3 and 3,5-T2 excretion was observed followed by a remarkable decrease, while a multifold and prolonged increase of the excretion of rT3, 3,3'-T2 and 3',5'-T2 was found. These data suggest an acute and remarkable effect of salicylate on T4 deiodinating pathway in the liver.
D000818:Animals; D001646:Bile / Q000378:metabolism*; D001659:Biliary Tract / Q000378:metabolism; D004104:Diiodothyronines / Q000378:metabolism; D007453:Iodide Peroxidase / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012459:Salicylates / Q000494:pharmacology*; D013963:Thyroid Hormones / Q000378:metabolism*; D013974:Thyroxine / Q000378:metabolism; D014284:Triiodothyronine / Q000378:metabolism*
D004104:Diiodothyronines; D012459:Salicylates; D013963:Thyroid Hormones; D014284:Triiodothyronine; C030103:3,5-diiodothyronine; C030102:3',5'-diiodothyronine; C030629:3,3'-diiodothyronine; D007453:Iodide Peroxidase; D013974:Thyroxine