Influence of brain catecholamines on the development of fatigue in exercising rats in the heat
Influence of brain catecholamines on the development of fatigue in exercising rats in the heat
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DOI：
10.1113/jphysiol.2007.142190
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发表时间：
2008-01-01
影响因子：
5.5
通讯作者：
Mecusen, Romain
中科院分区：
文献类型：
--
作者：
Hasegawa, Hiroshi;Piacentini, Maria Francesca;Mecusen, Romain
本研究旨在观察急性注射多巴胺（DA）/去甲肾上腺素（NA）双重再摄取抑制剂安非他酮（bupropion）对高温运动大鼠运动能力、体温调节及视前区和下丘脑前部（PO/AH）神经递质的影响。测量了体核温度（T-core）、脑温度（T-brain）和尾部皮肤温度（T-tail）。将微透析探针插入PO/AH，收集细胞外DA、NA和5-HT水平。大鼠在运动开始前20分钟接受安非他酮（17 mg kg（-1）;热BUP）或盐水（1 ml kg（-1）;热），并在温暖的环境（30 ℃）中以26 m/min（-1）的速度跑步直到筋疲力尽。大鼠也在凉爽的环境（18摄氏度;凉爽）中跑步直到筋疲力尽。环境温度对跑至力竭的时间有显著影响，在高温下，安非他酮会增加跑至力竭的时间（冷，143.6 +/- 21 min;热，65.8 +/- 13 min;热-BUP，86.3 +/- 7.2 min）。与冷组和热组相比，安非他酮组在疲劳时的T核心和T脑分别显著升高。在两种热条件下，在耗尽时测量的T尾没有显著差异。PO/AH细胞外DA、NA浓度随运动时间的延长而升高，安非他酮组显著高于冷、热组（P < 0.05）。组间5-HT水平无差异。这些结果表明，PO/AH中的DA和NA可能是安非他酮组在高温下运动能力和Tcore和T-脑增加的原因。此外，这些结果支持了先前在人类中的发现，即急性安非他酮摄入增加了高温运动期间的T核心，表明DA和NA在体温调节中可能发挥重要作用。
The purpose of the present studywas to identify the effects of an acute injection of a dual dopamine (DA)/noradrenaline (NA) reuptake inhibitor (bupropion) on exercise performance, thermoregulation and neurotransmitters in the preoptic area and anterior hypothalamus (PO/AH) of the rat during exercise in the heat. Body core temperature (T-core), brain temperature (T-brain) and tail skin temperature (T-tail) were measured. Amicrodialysis probe was inserted in the PO/AH, and samples for measurement of extracellular DA, NA and serotonin (5-HT) levels were collected. Rats received either bupropion (17 mg kg(-1); hot-BUP) or saline (1 ml kg(-1); hot) 20 min before the start of exercise and ran at a speed of 26 m min(-1) until exhaustion in awarm environment (30 degrees C). Rats also ran until exhaustion in a cool environment (18 degrees C; cool). Running time to exhaustion was significantly influenced by the ambient temperature, and it was increased by bupropion in the heat (cool, 143.6 +/- 21 min; hot, 65.8 +/- 13 min; hot-BUP, 86.3 +/- 7.2 min). T-core and T-brain at exhaustion were significantly higher in the bupropion group compared to the cool and hot groups, respectively. T-tail measured at exhaustion was not significantly different between the two hot conditions. Extracellular concentrations of DA and NA in the PO/AH increased during exercise, and was significantly higher in the bupropion than in cool and hot groups (P < 0.05). No differences were observed between groups for 5-HT levels. These results suggest that DA and NA in the PO/AH might be responsible for the increase in exercise performance and Tcore and T-brain in the bupropion group in hyperthermia. Moreover, these results support previous findings in humans that acute bupropion ingestion increases T-core during exercise in the heat, indicating the possibility of an important role for DA and NA in thermoregulation.