Rodrigues Quézia Teixeira, Drummond Lucas Rios, Lima Paulo Marcelo Andrade, Machado Frederico Sander Mansur, Campos Helton Oliveira, Szawka Raphael Escorsim, Leite Laura Hora Rios, Coimbra Cândido Celso
Departamento de Fisiologia e Biofísica, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
Departamento de Educação Física, Universidade do Estado de Minas Gerais, Unidade Divinópolis, Divinópolis, Minas Gerais, Brazil.
Behav Brain Res. 2025 Mar 5;480:115406. doi: 10.1016/j.bbr.2024.115406. Epub 2024 Dec 24.
Acting centrally, dopamine has been shown to induce ergogenic effects derived from its influence on thermoregulation, motivation, reward, and motor control. Thus, to evaluate the role of the central dopaminergic system in hypothalamic neuronal activation and its relationship with exercise performance, Wistar rats were intracerebroventricularly injected with saline (SAL) or SCH-23390 (SCH, dopamine D1 receptor blocker) at rest and before timed submaximal exercise (∼13 min) or exercise until fatigue. Core body and tail temperatures were recorded throughout the exercise. Hypothalamic Fos immunoreactivity (c-Fos-ir) expression was evaluated in thermoregulatory areas such as the median preoptic nucleus (MnPO), medial preoptic nucleus (MPO), paraventricular nucleus (PVN) and supraoptic nucleus (SON). Despite unchanged thermoregulatory adjustments, central D1 receptor blockade markedly decreased the exercise time and the workload performed until fatigue. Subsequently to timed exercise, D1 blockade increased neuronal activation in the MnPO, PVN, and SON. However, c-Fos-ir expression in the MnPO, MPO, PVN, and SON was similar between treated and control animals at fatigue. The data indicate that dopamine D1 receptors modulate exercise performance by altering hypothalamic neuronal activation elicited by exercise.
中枢作用方面，多巴胺已被证明可通过其对体温调节、动机、奖赏和运动控制的影响产生促力效应。因此，为了评估中枢多巴胺能系统在下丘脑神经元激活中的作用及其与运动表现的关系，将Wistar大鼠在静息时以及定时次最大运动（约13分钟）或运动至疲劳前进行脑室内注射生理盐水（SAL）或SCH-23390（SCH，多巴胺D1受体阻滞剂）。在整个运动过程中记录核心体温和尾温。在体温调节区域如视前正中核（MnPO）、内侧视前核（MPO）、室旁核（PVN）和视上核（SON）评估下丘脑Fos免疫反应性（c-Fos-ir）表达。尽管体温调节调整未改变，但中枢D1受体阻断显著缩短了运动时间和直至疲劳时所完成的工作量。定时运动后，D1阻断增加了MnPO、PVN和SON中的神经元激活。然而，在疲劳时，处理组和对照组动物的MnPO、MPO、PVN和SON中的c-Fos-ir表达相似。数据表明，多巴胺D1受体通过改变运动引起的下丘脑神经元激活来调节运动表现。
