Tryptophan-induced central fatigue in exercising rats is related to serotonin content in preoptic area
Tryptophan-induced central fatigue in exercising rats is related to serotonin content in preoptic area
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DOI：
10.1016/j.neulet.2007.01.035
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发表时间：
2007-03-30
影响因子：
2.5
通讯作者：
Marubayashi, Umeko
中科院分区：
文献类型：
--
作者：
Soares, Danusa Dias;Coimbra, Candido Celso;Marubayashi, Umeko
为了评估下丘脑色氨酸（TRP）对视前区5-羟色胺含量增加对跑步机运动时体温调节和工作效率的影响，20.3 μ M的L-TRP （n = 7）或0。在雄性Wistar大鼠开始跑步前立即向侧脑室注射15 M NaC1 (n = 6) （18 M min(-1) 5%倾斜度）。分析运动至疲劳时间（min）和运动负荷（kgm）。用遥测法测量核心温度。疲劳时迅速取脑，迅速解剖视前区（POA）、下丘脑（HP）、额叶皮质（FQ）、海马（HQ），立即干冰冷冻。HPLC法测定血清素（5-HT）和5-羟基吲哚乙酸（5-HIAA）含量。与休息和sal运动大鼠相比，trp运动大鼠的POA中5-HT含量最高，海马中5-HT含量最低。观察到TF与体温变化和POA-5HT水平的直接相关呈反比关系。HC - 5-HT含量与TF之间也存在相关性。然而，h5 - ht含量与疲劳时Tb的变化没有相关性。最后，我们的研究结果进一步证明，POA中5-HT含量的增加与运动时产热的增加有关。此外，trp运动大鼠海马5-HT水平与TF的直接相关性表明，该脑区也与运动时的运动活动控制有关。综上所述，我们的数据表明色氨酸引起的运动大鼠中枢疲劳与视前区血清素含量有关。2007爱思唯尔爱尔兰有限公司版权所有。
To assess the effects of increased hypothalamic tryptophan (TRP) availability on 5-HT content in preoptic area on thermoregulation and work production during exercise on treadmill, 20.3 mu M of L-TRP (n = 7) or 0. 15 M NaC1 (n = 6) was injected into the lateral cerebral ventricle of male Wistar rats immediately before the animals started running (18 m min(-1) 5% inclination). Exercise time to fatigue (min), and workload (kgm) were analysed. Core temperature was measured by telemetry. At fatigue, brains were quickly removed and preoptic area (POA), hypothalamus (HP), frontal cortex (FQ, hippocampi (HQ were rapidly dissected and frozen immediately in dry ice. Serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were measured by HPLC. TRP-exercised rats showed the highest content of 5-HT in the POA and the lowest in the hippocampi compared to the rested and SAL-exercised rats. An inverse relationship between TF and a direct correlation with body temperature changes and POA-5HT levels were observed. A correlation between HC 5-HT content and TF was also found. However, there was no correlation between HC 5-HT content and changes in Tb at fatigue. Finally, our results bring further evidences that increased 5-HT content in POA is involved with an increase in heat production during exercise. In addition, the direct correlation of 5-HT level in hippocampi and TF of TRP-exercised rats suggests that this brain area is also related to motor activity control during exercise. In conclusion, our data indicated that tryptophan- induced central fatigue in exercising rats is related to serotonin content in preoptic area. (c) 2007 Elsevier Ireland Ltd. All rights reserved.