Thyroid hormone biochemistry

While this pattern of biochemistry does not exclude transient relapse of Graves hyperthyroidism (despite the finding of negative TSH receptor antibodies), or a transient thyroiditis, the authors speculated that indinavir (prescribed in this patient together with stavudine and lamivudine) had inhibited the glucuronidation of thyroxine and hence caused a rise in serum thyroid hormone concentrations. 

Parker, S.J. and Specker, J.L. (1990). Salinity and temperature effects on whole-animal thyroid hormone levels in larval and juvenile striped bass, Morone saxatilis. Fish Physiology and Biochemistry 8,507-514. 

There are many reviews available on the biochemistry of thyroid hormones27-30 including the excellent review by Doonan in this Series1. Biosynthesis and metabolism of thyroid hormones will be reviewed briefly in this chapter. Attention will be given to recent developments relating to the mechanisms responsible for the physiological responses to thyroid hormones. 

The thyroid-pituitary-hypothalamus axis controls thyroid hormone homeostasis. Thyrotropin-releasing hormone (TRH), released from the hypothalamus, stimulates the synthesis and release of thyroid-stimulating hormone (thyrotropin, TSH) from the anterior pituitary. TSH increases the release of thyroid hormones by several mechanisms, including stimulation of the I pump. While lower than normal levels of T3 and T4 cause an exaggerated response of the pituitary to TRH, released thyroid hormones, in feedback control, blunt the stimulating action of TRH on the pituitary. For further discussion of TSH and TRH biochemistry, see, for example, the review by Kannan48. 

Lee SS and McCormickDB (1985) Thyroid hormone regulation of flavocoenzymebiosyn-thesis. Archives of Biochemistry and Biophysics 237,197-201. 

Numerous methods have been developed for assessing the concentrations of FT4 and FT3 in serum. These methods include direct assays that currently serve as reference methods and indirect assays that are more widely available for general laboratory use. The following section describes the principles of these methods and offers some guidelines for their use. The theoretical basis, analytical validity, and clinical utility of these methods have been discussed. Special reports from the Nomenclature Committee of the American Thyroid Association, the National Academy of Clinical Biochemistry, and the NCCLS also review some of the issues and concerns regarding free thyroid hormone measurements. 

Marimuthu, A. et al. (2002) Design of thyroid hormone receptor antagonists from first principles. Journal of Steroid Biochemistry and Molecular Biology, 83, 59-73. 

F4. Fontaine, Y. A., and Condliffe, P. G., Density gradient centrifugation of bovine thyroid-stimulating hormone. Biochemistry 2, 290-293 (1963). 

Sulakhe, S. J., S. T. Tran, and V. B. Pulga. 1990. Modulation of gamma-glutamyltranspep-tidase activity in rat liver membranes by thyroid hormones. International Journal of Biochemistry 22 997-1004. 

Ekholm R, Bjorkman U, Biochemistry of thyroid hormones. In Martini L, ed. The Thyroid Gland. New York Raven Press, 1990 83-125. 

Van der Ven et al. (2006) studied the effects of a number of PBDE congeners on thyroid hormones, blood biochemistry, and organ weights in adult rats. DecaBDE decreased T3 levels, thymus weight, and brain weight. DecaBDE was less active than other congeners" (p. 15). 

Shih, A., Lin, H.Y., Davis, F.B., and Davis, P.J., Thyroid hormone promotes serine phosphorylation of p53 by mitogen-activated protein kinase. Biochemistry, 40 (9), 2870-2878,... 

In its present state, the chromatography of I labeled substances is extremely useful for studying all processes involved in the biochemistry and physiol< of iodine and thyroid hormones. The principle of this type of analysis will probably be used for a reasonably long time, but modifications are to be expected soon, thanks to the introduction of new solvents and to the development of separation of column adsorbates by automatic fraction collection of their eluates. The use of substrates labeled with I and with other isotopes having different half-life spans will allow a more precise study of the biosjmthesis and fate of the two hormone derivatives, Tx and TRITh, which are now known. However, much work has been done with available techniques and they will still be... 

Ismail AAA, Walker PL, Barth JH, Lewandowski KC, lones R, Burr WA. Wrong biochemistry results two case reports and observational study in 5310 patients on potentially misleading thyroid-stimulating hormone and gonadotropin immunoassay results. Clin Chem 2002 48 2023-9. 

Barrett EJ. The thyroid gland. In Boron WF, Boulpaep EL. Medical Physiology A Cellular and Molecular Approach. Philadelphia, PA W.B. Saunders, 2003. Litwack G, Schmidt TJ. Biochemistry of hormones I polypeptide hormones. In Devlin TM, ed. Textbook of Biochemistry with Clinical Correlations, 5th ed. New York Wiley-Liss, 2002. 

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