Abstract
Studies on peripheral metabolism of simultaneously administered 125-I-labeled L-thyroxine ([125-I]T4) and 131-I labeled L-trilodothyronine ([131-I]T3) were performed in five normal subjects, in four patients with untreated hypothyroidism, and in 3 hypothyroid patients made euthyroid by the administration of T4. The fractional turnover rate (lambda 03) of thyroid hormones irreversibly leaving the site of degradation and the volumes of pool 1 (serum V1) of pool (interstitial fluid, V2), and of pool 3 (all tissues, V3)were obtained by using a three-compartment analysis. In addition to the turnover studies, the ratios for the in vivo T4 to T3 conversion were determined by paper chromatographic study in sera obtained 4, 7, and 10 daysafter the injection. The rate (K12) of the extrathyroidal conversion of T4 to T3 was also estimated by the compartment analysis. The T3 distribution volume (V3) of pool 3, in which T3 is utilized and degraded, was about 60% of totaldistribution volume (V=V1+V2+V3) in normal subjects, whereas only about 25% of the extrathyroidal T4 pool was in the intracellular compartment, indicating that T3 is predominantly an intracellular hormone..
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Selected References
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- Bellabarba D., Peterson R. E., Sterling K. An improved method for chromatography of iodothyronines. J Clin Endocrinol Metab. 1968 Feb;28(2):305–307. doi: 10.1210/jcem-28-2-305. [DOI] [PubMed] [Google Scholar]
- Braverman L. E., Ingbar S. H., Sterling K. Conversion of thyroxine (T4) to triiodothyronine (T3) in athyreotic human subjects. J Clin Invest. 1970 May;49(5):855–864. doi: 10.1172/JCI106304. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Braverman L. E., Vagenakis A., Downs P., Foster A. E., Sterling K., Ingbar S. H. Effects of replacement doses of sodium L-thyroxine on the peripheral metabolism of thyroxine and triiodothyronine in man. J Clin Invest. 1973 May;52(5):1010–1017. doi: 10.1172/JCI107265. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cavalieri R. R., Searle G. L. The kinetics of distribution between plasma and liver of 131-I-labeled L-thyroxine in man: observations of subjects with normal and decreased serum thyroxine-binding globulin. J Clin Invest. 1966 Jun;45(6):939–949. doi: 10.1172/JCI105409. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cavalieri R. R., Steinberg M., Searle G. L. Metabolic clearance rate of L-triiodothyronine in man: a comparison of results by single-injection and constant infusion methods. J Clin Endocrinol Metab. 1971 Oct;33(4):624–629. doi: 10.1210/jcem-33-4-624. [DOI] [PubMed] [Google Scholar]
- FISHER D. A., ODDIE T. H. WHOLE-BODY COUNTING OF 131-I-LABELED TRIIODOTHYRONINE. J Clin Endocrinol Metab. 1964 Aug;24:733–739. doi: 10.1210/jcem-24-8-733. [DOI] [PubMed] [Google Scholar]
- Fisher D. A., Chopra I. J., Dussault J. H. Extrathyroidal conversion of thyroxine to triiodothyronine in sheep. Endocrinology. 1972 Oct;91(4):1141–1144. doi: 10.1210/endo-91-4-1141. [DOI] [PubMed] [Google Scholar]
- Fisher D. A., Dussault J. H. Contribution of methodological artifacts to the measurement of T3 concentration in serum. J Clin Endocrinol Metab. 1971 May;32(5):675–679. doi: 10.1210/jcem-32-5-675. [DOI] [PubMed] [Google Scholar]
- Gharib H., Ryan R. J., Mayberry W. E., Hockert T. Radioimmunoassay for triiodothyronine (T 3 ): I. Affinity and specificity of the antibody for T 3 . J Clin Endocrinol Metab. 1971 Sep;33(3):509–516. doi: 10.1210/jcem-33-3-509. [DOI] [PubMed] [Google Scholar]
- Gregerman R. I., Solomon N. Acceleration of thyroxine and triiodothyronine turnover during bacterial pulmonary infections and fever: implications for the functional state of the thyroid during stress and in senescence. J Clin Endocrinol Metab. 1967 Jan;27(1):93–105. doi: 10.1210/jcem-27-1-93. [DOI] [PubMed] [Google Scholar]
- INADA M., KOSHIYAMA K., TORIZUKA K., AKAGI H., MIYAKE T. CLINICAL STUDIES ON THE METABOLISM OF 131-I-LABELED L-THYROXINE. J Clin Endocrinol Metab. 1964 Aug;24:775–784. doi: 10.1210/jcem-24-8-775. [DOI] [PubMed] [Google Scholar]
- Inada M., Okabe J., Kazama Y., Takayama H., Nakagawa T., Torizuka K. Thyroxine turnover and transport in diabetes mellitus. J Clin Endocrinol Metab. 1973 Mar;36(3):590–597. doi: 10.1210/jcem-36-3-590. [DOI] [PubMed] [Google Scholar]
- Inada M., Sterling K. Thyroxine Turnover and Transport in Laennec's Cirrhosis of the Liver. J Clin Invest. 1967 Aug;46(8):1275–1282. doi: 10.1172/JCI105620. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Larsen P. R. Technical aspects of the estimation of triiodothyronine in human serum: evidence of conversion of thyroxine to triiodothyronine during assay. Metabolism. 1971 Jun;20(6):609–624. doi: 10.1016/0026-0495(71)90009-6. [DOI] [PubMed] [Google Scholar]
- MURPHY B. E., PATTEE C. J. DETERMINATION OF THYROXINE UTILIZING THE PROPERTY OF PROTEIN-BINDING. J Clin Endocrinol Metab. 1964 Feb;24:187–196. doi: 10.1210/jcem-24-2-187. [DOI] [PubMed] [Google Scholar]
- McConnon J., Row V. V., Volpe Simultaneous comparative studies of thyroxine and tri-iodothyronine distribution and disposal rates. J Endocrinol. 1971 Sep;51(1):17–30. doi: 10.1677/joe.0.0510017. [DOI] [PubMed] [Google Scholar]
- Nicoloff J. T., Dowling J. T. Estimation of thyroxine distribution in man. J Clin Invest. 1968 Jan;47(1):26–37. doi: 10.1172/JCI105712. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Nicoloff J. T., Low J. C., Dussault J. H., Fisher D. A. Simultaneous measurement of thyroxine and triiodothyronine peripheral turnover kinetics in man. J Clin Invest. 1972 Mar;51(3):473–483. doi: 10.1172/JCI106835. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Oddie T. H., Fisher D. A., Dussault J. H., Thompson C. S. Triiodothyronine turnover in euthyroid subjects. J Clin Endocrinol Metab. 1971 Oct;33(4):653–660. doi: 10.1210/jcem-33-4-653. [DOI] [PubMed] [Google Scholar]
- Oddie T. H., Meade J. H., Jr, Fisher D. A. An analysis of published data on thyroxine turnover in human subjects. J Clin Endocrinol Metab. 1966 Apr;26(4):425–436. doi: 10.1210/jcem-26-4-425. [DOI] [PubMed] [Google Scholar]
- Oppenheimer J. H., Bernstein G., Hasen J. Estimation of rapidly exchangeable cellular thyroxine from the plasma disappearance curves of simultaneously administered thyroxine-131-I and albumin-125-I. J Clin Invest. 1967 May;46(5):762–777. doi: 10.1172/JCI105577. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Oppenheimer J. H., Schwartz H. L., Shapiro H. C., Bernstein G., Surks M. I. Differences in primary cellular factors influencing the metabolism and distribution of 3,5,3'-L-triiodothyronine and L-thyroxine. J Clin Invest. 1970 May;49(5):1016–1024. doi: 10.1172/JCI106301. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Pittman C. S., Chambers J. B., Jr, Read V. H. The extrathyroidal conversion rate of thyroxine to triiodothyronine in normal man. J Clin Invest. 1971 Jun;50(6):1187–1196. doi: 10.1172/JCI106596. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Refetoff S., Matalon R., Bigazzi M. Metabolism of L-thyroxine (T4) and L-triiodothyronine (T3) by human fibroblasts in tissue culture: evidence for cellular binding proteins and conversion of T4 to T3. Endocrinology. 1972 Oct;91(4):934–947. doi: 10.1210/endo-91-4-934. [DOI] [PubMed] [Google Scholar]
- SKINNER S. M., CLARK R. E., BAKER N., SHIPLEY R. A. Complete solution of the three-compartment model in steady state after single injection of radioactive tracer. Am J Physiol. 1959 Feb;196(2):238–244. doi: 10.1152/ajplegacy.1959.196.2.238. [DOI] [PubMed] [Google Scholar]
- STERLING K., CHODOS R. B. Radiothyroxine turnover studies in myxedema, thyrotoxicosis, and hypermetabolism without endocrine disease. J Clin Invest. 1956 Jul;35(7):806–813. doi: 10.1172/JCI103333. [DOI] [PMC free article] [PubMed] [Google Scholar]
- STERLING K., LASHOF J. C., MAN E. B. Disappearance from serum of I131-labeled l-thyroxine and l-triiodothyronine in euthyroid subjects. J Clin Invest. 1954 Jul;33(7):1031–1035. doi: 10.1172/JCI102970. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Schwartz H. L., Surks M. I., Oppenheimer J. H. Quantitation of extrathyroidal conversion of L-thyroxine to 3,5,3'-triiodo-L-thyronine in the rat. J Clin Invest. 1971 May;50(5):1124–1130. doi: 10.1172/JCI106584. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Silvers A., Swenson R. S., Farquhar J. W., Reaven G. M. Derivation of a three compartment model describing disappearance of plasma insulin-131-I in man. J Clin Invest. 1969 Aug;48(8):1461–1469. doi: 10.1172/JCI106112. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Singer P. A., Nicoloff J. T. Estimation of the triodothyronine secretion rate in euthyroid man. J Clin Endocrinol Metab. 1972 Jul;35(1):82–89. doi: 10.1210/jcem-35-1-82. [DOI] [PubMed] [Google Scholar]
- Sterling K., Bellabarba D., Newman E. S., Brenner M. A. Determination of triiodothyronine concentration in human serum. J Clin Invest. 1969 Jun;48(6):1150–1158. doi: 10.1172/JCI106072. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sterling K., Brenner M. A. Free thyroxine in human serum: simplified measurement with the aid of magnesium precipitation. J Clin Invest. 1966 Jan;45(1):153–163. doi: 10.1172/JCI105320. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Sterling K., Brenner M. A., Newman E. S. Conversion of thyroxine to triiodothyronine in normal human subjects. Science. 1970 Sep 11;169(3950):1099–1100. doi: 10.1126/science.169.3950.1099. [DOI] [PubMed] [Google Scholar]
- Sterling K., Brenner M. A., Saldanha V. F. Conversion of thyroxine to triiodothyronine by cultured human cells. Science. 1973 Mar 9;179(4077):1000–1001. doi: 10.1126/science.179.4077.1000. [DOI] [PubMed] [Google Scholar]
- Surks M. I., Oppenheimer J. H. Formation of iodoprotein during the peripheral metabolism of 3,5,3'-triiodo-L-thyronine-125I in the euthyroid man and rat. J Clin Invest. 1969 Apr;48(4):685–695. doi: 10.1172/JCI106026. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Surks M. I., Schadlow A. R., Stock J. M., Oppenheimer J. H. Determination of iodothyronine absorption and conversion of L-thyroxine (T 4 ) to L-triiodothyronine (T 3 ) using turnover rate techniques. J Clin Invest. 1973 Apr;52(4):805–811. doi: 10.1172/JCI107244. [DOI] [PMC free article] [PubMed] [Google Scholar]
- TAUROG A. Spontaneous deiodination of I-131-labeled thyroxine and related iodophenols on filter paper. Endocrinology. 1963 Jul;73:45–56. doi: 10.1210/endo-73-1-45. [DOI] [PubMed] [Google Scholar]
- Woeber K. A., Hecker E., Ingbar S. H. The effects of an acute load of thyroxine on the transport and peripheral metabolism of triiodothyronine in man. J Clin Invest. 1970 Apr;49(4):650–654. doi: 10.1172/JCI106276. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Woeber K. A., Sobel R. J., Ingbar S. H., Sterling K. The peripheral metabolism of triiodothyronine in normal subjects and in patients with hyperthyroidism. J Clin Invest. 1970 Apr;49(4):643–649. doi: 10.1172/JCI106275. [DOI] [PMC free article] [PubMed] [Google Scholar]
