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Positive correlation between type 1 and 2 iodothyronine deiodinases activities in human goiters.
Pereira, Valmara S; Marassi, Michelle P; Rosenthal, Doris; Vaisman, Mário; Corrêa da Costa, Vânia M.
Afiliação
  • Pereira VS; Laboratório de Fisiologia Endócrina Doris Rosenthal, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, CCS, bloco G, Cidade Universitária, Ilha do Fundão, Rio de Janeiro, 21949-900, Brazil.
Endocrine ; 41(3): 532-8, 2012 Jun.
Article em En | MEDLINE | ID: mdl-22207295
Type 1 (D1) and 2 (D2) iodothyronine deiodinases are selenocysteine-containing enzymes that catalyze the deiodination of T4 to T3 in the thyroid and in peripheral tissues. Despite their importance to the plasma T3 pool in human beings, there are few studies about their behavior in human thyroids. In order to better understand iodothyronine deiodinase regulation in the thyroid gland, we studied thyroid tissue samples from follicular adenoma (AD, n = 5), toxic diffuse goiter (TDG, n = 6), nontoxic multinodular goiter (NMG, n = 40), papillary thyroid carcinoma (PTC, n = 8), and surrounding normal tissues (NT, n = 7) from 36 patients submitted to elective thyroidectomy. D1 and D2 activities were determined by quantification of the radioiodine released by ¹²5I-rT3 or ¹²5I-T4 under standardized conditions, and expressed as pmol rT3 deiodinated per minute and mg protein (pmol rT3 min⁻¹ mg⁻¹ ptn) and fmol T4 deiodinated per minute and mg protein (fmol T4 min⁻¹ mg⁻¹ ptn), respectively. D1 activity detected in TDG and AD tissues were significantly higher than in NT, PTC or NMG samples. D2 activity was also significantly higher in TDG and AD samples than in PTC, NMG, or NT. There was great variability in D1 and D2 enzymatic activities from distinct patients as well as from different areas from the same goiter. There was a positive correlation (P < 0,0001, r = 0.4942) between D1 and D2 activities when all samples were taken into account, suggesting that-in the thyroid-these two iodothyronine deiodinases may have related regulatory mechanisms, even if conditioned by other as yet unknown factors.
Assuntos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Glândula Tireoide / Neoplasias da Glândula Tireoide / Bócio Nodular / Iodeto Peroxidase / Proteínas de Neoplasias Limite: Adolescent / Adult / Aged / Female / Humans / Male / Middle aged Idioma: En Revista: Endocrine Assunto da revista: ENDOCRINOLOGIA Ano de publicação: 2012 Tipo de documento: Article País de afiliação: Brasil País de publicação: Estados Unidos

Texto completo: 1 Coleções: 01-internacional Base de dados: MEDLINE Assunto principal: Glândula Tireoide / Neoplasias da Glândula Tireoide / Bócio Nodular / Iodeto Peroxidase / Proteínas de Neoplasias Limite: Adolescent / Adult / Aged / Female / Humans / Male / Middle aged Idioma: En Revista: Endocrine Assunto da revista: ENDOCRINOLOGIA Ano de publicação: 2012 Tipo de documento: Article País de afiliação: Brasil País de publicação: Estados Unidos