Zheng Xinyan, Takatsu Satomi, Ishikawa Ryo, Hasegawa Hiroshi
School of Kinesiology, Shanghai University of Sport, 188 Hengren Road, Yangpu, Shanghai 200438, China.
Graduate School of Faculty of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashihiroshima, Hiroshima 739-8521, Japan.
J Therm Biol. 2018 Jan;71:123-127. doi: 10.1016/j.jtherbio.2017.11.003. Epub 2017 Nov 9.
Thermoeffector responses and core body temperature (T) homeostasis during exercise are affected by both ambient temperature and exercise intensity. We have previously reported that T, heat loss responses, and catecholamine release in the preoptic area and anterior hypothalamus (PO/AH) increased during incremental treadmill running. However, no previous study has examined whether changes in the thermoregulatory responses at warm ambient temperature are related to catecholamine responses during moderate intensity exercise in rats. Therefore, the aim of the present study was to investigate the responsiveness of neurotransmission in the PO/AH to moderate intensity exercise at different ambient temperatures, and to relate this to changes in thermoregulation. We measured the monoamine levels in the PO/AH and the thermoregulatory responses in exercising rats simultaneously using a combination of methods, including in vivo microdialysis, biotelemetry, and animal O/CO metabolism measuring system. On the day of experiments, rats ran for 60min at a speed of 18mmin on a treadmill at a 5% gradient, in an ambient temperature of 23°C or 30°C. T, tail skin temperature (T; an index of heat loss), and oxygen consumption (V̇O: an index of heat production) were monitored. Dopamine (DA), noradrenaline (NA), and serotonin (5-HT) levels were measured by high performance liquid chromatography (HPLC) with electrochemical detection. Exercise significantly increased the T, T, and V̇O values, as well as DA and NA release in the PO/AH at both temperatures, and the increases were more pronounced at the warm ambient temperature. The results suggest that the increase in the T, heat production, and heat loss responses even during moderate intensity running in a warm environment are likely associated with an increase in DA and NA release in the PO/AH region.
运动过程中的温度效应器反应和核心体温（T）稳态受环境温度和运动强度的影响。我们之前报道过，在递增式跑步机跑步过程中，视前区和下丘脑前部（PO/AH）的体温、散热反应以及儿茶酚胺释放会增加。然而，之前没有研究探讨过在温暖环境温度下体温调节反应的变化是否与大鼠中等强度运动期间的儿茶酚胺反应有关。因此，本研究的目的是调查在不同环境温度下PO/AH中神经传递对中等强度运动的反应性，并将其与体温调节的变化联系起来。我们使用体内微透析、生物遥测和动物氧/二氧化碳代谢测量系统等多种方法相结合，同时测量运动大鼠PO/AH中的单胺水平和体温调节反应。在实验当天，大鼠在23°C或30°C的环境温度下，以18米/分钟的速度在5%坡度的跑步机上跑60分钟。监测体温、尾皮肤温度（T；散热指标）和耗氧量（V̇O：产热指标）。通过高效液相色谱（HPLC）结合电化学检测法测量多巴胺（DA）、去甲肾上腺素（NA）和5-羟色胺（5-HT）水平。运动显著增加了两个温度下的体温、T和V̇O值，以及PO/AH中的DA和NA释放，并且在温暖环境温度下增加更为明显。结果表明，即使在温暖环境中进行中等强度跑步时，体温、产热和散热反应的增加可能与PO/AH区域中DA和NA释放的增加有关。
