The effect of iodothyronines on the conversion of thyroxine into 3,3'-5-tri-iodothyronine in isolated rat renal tubules.
Isolated rat renal tubules prepared by collagenase digestion were used to study the effects of 3,3',5'-tri-iodothyronine ('reverse T3', rT3) and other iodothyronines on the formation of 3,3',5-tri-iodothyronine (T3) from thyroxine (T4). rT3 inhibited the conversion with a dose response over the concentration range 1.5nM-1.5microM. The inhibition was competitive in nature. Both 3,3'-di-iodothyronine and 3',5'-di-iodothyronine also inhibited the production of T3 and T4 in isolated rat renal tubules, but tetraiodothyroacetic acid and 3,5-di-iodothyronine were found to have no effect. These experiments demonstrate in an intact cell system that some naturally occurring iodothyronines have significant effects on T4 deiodination.
D000818:Animals; D003864:Depression, Chemical; D004305:Dose-Response Relationship, Drug; D066298:In Vitro Techniques; D007684:Kidney Tubules / Q000187:drug effects* / Q000378:metabolism; D051381:Rats; D013970:Thyronines / Q000494:pharmacology*; D013974:Thyroxine / Q000378:metabolism*; D014284:Triiodothyronine / Q000378:metabolism*
D013970:Thyronines; D014284:Triiodothyronine; D013974:Thyroxine