title: Type 2 iodothyronine deiodinase is upregulated in rat slow- and fast-twitch skeletal muscle during cold exposure.
abstract: During cold acclimation, shivering is progressively replaced by nonshivering thermogenesis. Brown adipose tissue (BAT) and skeletal muscle are relevant for nonshivering thermogenesis, which depends largely on thyroid hormone. Since the skeletal muscle fibers progressively adapt to cold exposure through poorly defined mechanisms, our intent was to determine whether skeletal muscle type 2 deiodinase (D2) induction could be implicated in the long-term skeletal muscle cold acclimation. We demonstrate that in the red oxidative soleus muscle, D2 activity increased 2.3-fold after 3 days at 4°C together with the brown adipose tissue D2 activity, which increased 10-fold. Soleus muscle and BAT D2 activities returned to the control levels after 10 days of cold exposure, when an increase of 2.8-fold in D2 activity was detected in white glycolytic gastrocnemius but not in red oxidative gastrocnemius fibers. Propranolol did not prevent muscle D2 induction, but it impaired the decrease of D2 in BAT and soleus after 10 days at 4°C. Cold exposure is accompanied by increased oxygen consumption, UCP3, and PGC-1α genes expression in skeletal muscles, which were partialy prevented by propranolol in soleus and gastrocnemius. Serum total and free T3 is increased during cold exposure in rats, even after 10 days, when BAT D2 is already normalized, suggesting that skeletal muscle D2 activity contributes significantly to circulating T3 under this adaptive condition. In conclusion, cold exposure is accompanied by concerted changes in the metabolism of BAT and oxidative and glycolytic skeletal muscles that are paralleled by type 2 deiodinase activation.
authors.affiliation: Laboratório de Fisiologia Endócrina Doris Rosenthal, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Laboratório de Biologia do Exercício, Escola de Educação Física e Desportos, Departamento de Biociências e Atividade Física - Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; and.
authors.forename: Ruy A
authors.initials: RA
authors.lastname: Louzada
authors.affiliation: Laboratório de Fisiologia Endócrina Doris Rosenthal, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil;
authors.forename: Maria C S
authors.initials: MC
authors.lastname: Santos
authors.affiliation: Laboratório de Fisiologia Endócrina Doris Rosenthal, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Laboratório de Biologia do Exercício, Escola de Educação Física e Desportos, Departamento de Biociências e Atividade Física - Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; and Laboratório de Fisiologia Mitocondrial e Bioenergética, Instituto de Bioquímica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: João Paulo A
authors.initials: JP
authors.lastname: Cavalcanti-de-Albuquerque
authors.affiliation: Laboratório de Biologia do Exercício, Escola de Educação Física e Desportos, Departamento de Biociências e Atividade Física - Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; and.
authors.forename: Igor F
authors.initials: IF
authors.lastname: Rangel
authors.affiliation: Laboratório de Fisiologia Endócrina Doris Rosenthal, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil;
authors.forename: Andrea C F
authors.initials: AC
authors.lastname: Ferreira
authors.affiliation: Laboratório de Fisiologia Mitocondrial e Bioenergética, Instituto de Bioquímica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: Antonio
authors.initials: A
authors.lastname: Galina
authors.affiliation: Laboratório de Biologia do Exercício, Escola de Educação Física e Desportos, Departamento de Biociências e Atividade Física - Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; and.
authors.forename: Joao Pedro S
authors.initials: JP
authors.lastname: Werneck-de-Castro
authors.affiliation: Laboratório de Fisiologia Endócrina Doris Rosenthal, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; dencarv@biof.ufrj.br.
authors.forename: Denise P
authors.initials: DP
authors.lastname: Carvalho
mesh_terms: D002001:Adipose Tissue, Brown / Q000378:metabolism; D000818:Animals; D001831:Body Temperature / Q000502:physiology; D002950:Citrate (si)-Synthase / Q000378:metabolism; D003080:Cold Temperature; D007453:Iodide Peroxidase / Q000096:biosynthesis*; D008297:Male; D018656:Muscle Fibers, Fast-Twitch / Q000378:metabolism*; D018657:Muscle Fibers, Slow-Twitch / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology; D051381:Rats; D017208:Rats, Wistar; D013974:Thyroxine / Q000378:metabolism; D014284:Triiodothyronine / Q000378:metabolism; D015854:Up-Regulation / Q000502:physiology; D000097564:Iodothyronine Deiodinase Type II
chemical_list: D002950:Citrate (si)-Synthase; D007453:Iodide Peroxidase; D013974:Thyroxine; D014284:Triiodothyronine; D000097564:Iodothyronine Deiodinase Type II
keywords: cold acclimation; deiodinase; skeletal muscle; thermogenesis; thyroid