Conversion of thyroxine into 3,5,3'-triiodothyronine and 3,3',5'-triiodothyronine in the young pig.
Estimates have been made of the amounts of 3,5,3'-triiodothyrone (T3) and 3,3',5'-triiodothyronine (rT3) derived from peripheral deiodination of thyroxine (T4) in young pigs. Two methods were used. The first depended on the assumption that deiodination occurs at the same rate in normal animals and in thyroidectomized animals on T4 replacement therapy. The second on the assumption that T3 and rT3 are secreted in the same proportions as they occur in thyroglobulin. The first method arguably gives the better estimate which is that 87% of circulating T4 is monodeiodinated to T3 and rT3. Peripheral conversion accounts for 76 and 69% of the circulating T3 and rT3, respectively.
Slebodziński
A B
AB
Ingram
D L
DL
Dauncey
M J
MJ
D000818:Animals; D013552:Swine; D013965:Thyroidectomy; D013974:Thyroxine / Q000378:metabolism*; D014284:Triiodothyronine / Q000096:biosynthesis*; D014285:Triiodothyronine, Reverse / Q000096:biosynthesis*
D014284:Triiodothyronine; D014285:Triiodothyronine, Reverse; D013974:Thyroxine