We have investigated thyroid hormone deiodination in the liver, kidney and thyroid of the domestic cat. Affinity labelling with (125)I-bromoacetyl reverse T(3) (125)(I-BrAc-rT(3) demonstrated that liver and kidney, but not the thyroid, express type I iodothyronine deiodinase (IDI), results that were confirmed by measuring the activity of the IDI using (125)I-rT(3) and T(4) as substrate. Feline ...
