THE METABOLIC PRODUCTS OF I¹³¹ LABELED THYROXINE IN VARIOUS RAT TISSUE SLICES

Abstract

1) By using the exchange method between L-thyroxine and inorganic radio iodine, it was succeed to get I¹³¹ labeled thyroxine with the high specific activity.
2) I¹³¹ labeled thyroxine was well metabolized by kidney and liver slice of rat, but not by the other peripheral tissue slices.
3) Kidney slice converted thyroxine into triiodotyronine (or diiodothyronine), inorganic iodide and two unknown compounds (U₃ and U₄).
4) Live slice converted thyroxine into unknown compounds (U₁ and U₃) and inorganic iodide, but not convert thyroxine into troiiodothyronine (or diiodothyronine) and the unknown compound named U₄.