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Horm Metab Res 1989; 21(8): 441-444
DOI: 10.1055/s-2007-1009257
Clinical

© Georg Thieme Verlag, Stuttgart · New York

Stimulation of the Chlorinating Activity of Human Myeloperoxidase by Thyroid Hormones and Analogues

J. M. Van Zyl, K. Basson, B. J. Van der Walt
  • Department of Pharmacology, University of Stellenbosch, Medical School, Tygerberg, South Africa
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Publication History

1988

1988

Publication Date:
24 April 2008 (online)

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Summary

Thyroxine and triiodothyronine concentrations of 50 nM or lower can stimulate the chlorinating activity of the myeloperoxidase-H2O2-Cl- antimicrobial system in vitro. The initial rates of the chlorinating reaction with monochlorodimedone were similar for both thyroid hormones. Maximum stimulation occurred around pH6 and a linear relationship exists between stimulation and thyroxine concentrations up to at least 1 μM. Of the various thyroxine analogues tested, stimulation was in the order: T4 (or T3) > triiodothyropropionic acid > 3,5-T2. Diiodotyrosine did not have any significant stimulatory effect. The oxidised product of the phenolic ring of T4, presumably a hydroxyquinone, may act as an additional electron carrier and thereby facilitates redox reactions.

Key words

Myeloperoxidase - Chlorinating Activity - Thyroid Hormones

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