dos Reis-Lunardelli Eleonora Araújo, Castro Cibele Canal, Bavaresco Caren, Coitinho Adriana Simon, da Trindade Laura Schumacher Schuh, Perrenoud Myriam Fortes, Roesler Rafael, Sarkis João José Freitas, de Souza Wyse Angela Terezinha, Izquierdo Iván
Departamento de Bioquímica, ICBS, Universidade Federal do Rio Grande do Sul, Rua Ramiro Barcelos, 2600 - Anexo, CEP 90035-003, Porto Alegre, RS, Brazil.
Curr Neurovasc Res. 2007 Aug;4(3):184-93. doi: 10.2174/156720207781387204.
Thyroid hormones (THs), including triiodothyronine (T3) and tetraiodothyronine (T4), are recognized as key metabolic hormones of the body. THs are essential for normal maturation and function of the mammalian central nervous system (CNS) and its deficiency, during a critical period of development, profoundly affects cognitive function. Sodium-potassium adenosine 5'-triphosphatase (Na(+), K(+)-ATPase) is a crucial enzyme responsible for the active transport of sodium and potassium ions in the CNS necessary to maintain the ionic gradient for neuronal excitability. Studies suggest that Na(+), K(+)-ATPase might play a role on memory formation. Moreover, THs were proposed to stimulate Na(+), K(+)-ATPase activity in the heart of some species. In this work we investigated the effect of a chronic administration of L-thyroxine (L-T4) or propylthiouracil (PTU), an antithyroid drug, on some behavioral paradigms: inhibitory avoidance task, open field task, plus maze and Y-maze, and on the activity of Na(+), K(+)-ATPase in the rat parietal cortex and hippocampus. By using treatments which have shown to induce alterations in THs levels similar to those found in hyperthyroid and hypothyroid patients, we aimed to understand the effect of an altered hyperthyroid and hypothyroid state on learning and memory and on the activity of Na(+), K(+)-ATPase. Our results showed that a hyper and hypothyroid state can alter animal behavior and they also might indicate an effect of THs on learning and memory.
甲状腺激素（THs），包括三碘甲状腺原氨酸（T3）和四碘甲状腺原氨酸（T4），被认为是人体关键的代谢激素。甲状腺激素对于哺乳动物中枢神经系统（CNS）的正常成熟和功能至关重要，在发育的关键时期其缺乏会深刻影响认知功能。钠钾腺苷三磷酸酶（Na(+)，K(+)-ATPase）是一种关键酶，负责中枢神经系统中钠和钾离子的主动转运，这对于维持神经元兴奋性的离子梯度是必需的。研究表明，Na(+)，K(+)-ATPase可能在记忆形成中发挥作用。此外，有人提出甲状腺激素可刺激某些物种心脏中的Na(+)，K(+)-ATPase活性。在这项工作中，我们研究了长期给予L-甲状腺素（L-T4）或抗甲状腺药物丙硫氧嘧啶（PTU）对一些行为范式的影响：抑制性回避任务、旷场任务、十字迷宫和Y迷宫，以及对大鼠顶叶皮质和海马体中Na(+)，K(+)-ATPase活性的影响。通过使用已证明能诱导甲状腺激素水平变化，类似于甲状腺功能亢进和甲状腺功能减退患者中发现的变化的治疗方法，我们旨在了解甲状腺功能亢进和减退状态改变对学习和记忆以及对Na(+)，K(+)-ATPase活性的影响。我们的结果表明，甲状腺功能亢进和减退状态会改变动物行为，它们也可能表明甲状腺激素对学习和记忆有影响。
