کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
2568654 1128471 2014 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Soy isoflavones interfere with thyroid hormone homeostasis in orchidectomized middle-aged rats
ترجمه فارسی عنوان
ایزوفلاونهای سویا با هوموستاز هورمون تیروئید در موش های صحرایی وحشی مبتلا می شوند
موضوعات مرتبط
علوم زیستی و بیوفناوری علوم محیط زیست بهداشت، سم شناسی و جهش زایی
چکیده انگلیسی


• We tested how genistein and daidzein interfere with thyroid hormone homeostasis.
• Thyroid: decreased expression of Tg and TPO genes correlated with IHC results.
• Serum: total T4 reduced and TSH increased.
• Liver and kidney: expression of Spot 14 and liver Dio 1 activity increased.
• Pituitary: expression of T3-regulated genes and Dio 1 and 2 activities unchanged.

We previously reported that genistein (G) and daidzein (D) administered subcutaneously (10 mg/kg) induce changes in the angio-follicular units of the thyroid gland, reduce concentration of total thyroid hormones (TH) and increase thyrotropin (TSH) in serum of orchidectomized middle-aged (16-month-old) rats. To further investigate these effects, we now examined expression levels of the thyroglobulin (Tg), thyroperoxidase (Tpo), vascular endothelial growth factor A (Vegfa) and deiodinase type 1 (Dio 1) genes in the thyroid; in the pituitary, genes involved in TH feedback control (Tsh β, Dio 1, Dio 2, Trh receptor); and in the liver and kidney, expression of T3-activated genes Dio 1 and Spot 14, as well as transthyretin (Ttr), by quantitative real-time PCR. We also analyzed TPO-immunopositivity and immunofluorescence of T4 bound to Tg, determined thyroid T4 levels and measured deiodinase enzyme activities in examined organs. Decreased expression of Tg and Tpo genes (p < 0.05) correlated with immunohistochemical staining results, and together with decreased serum total T4 levels, indicates decreased Tg and TH synthesis following treatments with both isoflavones. However, expression of Spot 14 (p < 0.05) gene in liver and kidney was up-regulated, and liver Dio 1 expression and activity (p < 0.05) increased. At the level of pituitary, no significant change in gene expression levels, or Dio 1 and 2 enzyme activities was observed. In conclusion, both G and D impaired Tg and TH synthesis, but at the same time increased tissue availability of TH in peripheral tissues of Orx middle-aged rats.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Toxicology and Applied Pharmacology - Volume 278, Issue 2, 15 July 2014, Pages 124–134
نویسندگان
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