Fortunato Rodrigo Soares, Ignácio Daniele Leão, Padron Alvaro Souto, Peçanha Ramon, Marassi Michelle Porto, Rosenthal Doris, Werneck-de-Castro João Pedro Saar, Carvalho Denise P
Laboratorio de Fisiologia Endócrina Doris Rosenthal Laboratório de Cardiologia Celular e Molecular, Universidade Federal do Rio de Janeiro, Instituto de Biofísica Carlos Chagas Filho, Rio de Janeiro 21941-902, Brazil.
J Endocrinol. 2008 Aug;198(2):347-53. doi: 10.1677/JOE-08-0174. Epub 2008 Jun 6.
The hypothalamic-pituitary-thyroid axis is affected by acute exercise, but the mechanisms underlying thyroid function changes after exercise remain to be defined. The aim of this study was to elucidate the effects of a session of acute exercise on the treadmill at 75% of maximum oxygen consumption on thyroid function of rats. Male Wistar rats were divided into five groups: control (without exercise), and killed immediately after (0 min) or 30, 60, and 120 min after the end of the exercise session. A significant increase in serum tri-iodothyronine (T(3)) occurred immediately after the exercise, with a gradual decrease thereafter, so that 120 min after the end of the exercise, serum T(3) was significantly lower than that in controls. Total thyroxine (T(4)) increased progressively reaching values significantly higher than that in the control group at 120 min. T(3)/T(4) ratio was significantly decreased 60 and 120 min after the exercise, indicating impaired T(4)-to-T(3) conversion. Liver type 1 deiodinase activity (D1) significantly decreased at 60 and 120 min, while pituitary D1 increased progressively from 30 to 120 min after the exercise, and thyroid D1 was increased only immediately after the end of the exercise. Brown adipose tissue (BAT) type 2 deiodinase activity (D2) was significantly lower at 30 min, but pituitary D2 remained unchanged. No change in serum thyrotropin was detected, while serum corticosterone was significantly higher 30 min after the exercise. Our results demonstrate that decreased liver D1 and BAT D2 might be involved in the decreased T(4)-to-T(3) conversion detected after an exercise session on the treadmill.
下丘脑 - 垂体 - 甲状腺轴受急性运动影响，但运动后甲状腺功能变化的潜在机制仍有待明确。本研究旨在阐明在跑步机上以最大耗氧量的75%进行一次急性运动对大鼠甲状腺功能的影响。雄性Wistar大鼠分为五组：对照组（不运动），在运动结束后立即（0分钟）或30、60和120分钟后处死。运动后血清三碘甲状腺原氨酸（T(3)）立即显著升高，此后逐渐下降，因此在运动结束120分钟后，血清T(3)显著低于对照组。总甲状腺素（T(4)）逐渐升高，在120分钟时达到显著高于对照组的值。运动后60和120分钟，T(3)/T(4)比值显著降低，表明T(4)向T(3)的转化受损。肝脏1型脱碘酶活性（D1）在60和120分钟时显著降低，而垂体D1在运动后30至120分钟逐渐升高，甲状腺D1仅在运动结束后立即升高。棕色脂肪组织（BAT）2型脱碘酶活性（D2）在30分钟时显著降低，但垂体D2保持不变。未检测到血清促甲状腺激素的变化，而运动后30分钟血清皮质酮显著升高。我们的结果表明，肝脏D1和BAT D2的降低可能与在跑步机上运动后检测到的T(4)向T(3)转化减少有关。
