Preferential renal excretion of iodide derived from thyroxine and triiodothyronine deiodination in man.
Tracer doses of 131I- (Carrier free), 131I-T3 and 131-T4 were administered po to 19 healthy male volunteers at intervals 2 to 8 weeks to study whether or not part of the iodide generated in the kidney from T3 and T4 deiodination may enter the renal tubular lumen and be excreted in the urine without entering the blood stream. U(urine)/T(thyroid) ratios of the radioactivity from these materials were employed as the index of the comparison. U/T ratios were severalfold higher 24 h after 131I-T3 or 131I-T4 administration than after 131I-. The data indicate that the 131I- derived from T3 and T4 metabolism is more readily excreted into urine than 131I- which reaches the kidney as inorganic iodide.
D006801:Humans; D007454:Iodides / Q000378:metabolism* / Q000652:urine; D007668:Kidney / Q000378:metabolism*; D008297:Male; D013961:Thyroid Gland / Q000378:metabolism*; D013963:Thyroid Hormones / Q000378:metabolism*; D013974:Thyroxine / Q000378:metabolism / Q000652:urine; D013997:Time Factors; D014284:Triiodothyronine / Q000378:metabolism / Q000652:urine
D007454:Iodides; D013963:Thyroid Hormones; D014284:Triiodothyronine; D013974:Thyroxine