耐力训练后大鼠纹状体、中脑和下丘脑单胺类神经递质的变化

Changes of monoamine neurotransmitter concentrations in striatum, midbrain and hypothalamus of rats after endurance training

目的:分析不同脑区单胺类神经递质对运动耐力训练应激的反应。方法:实验于2002-07/2003-07在南京体育学院和南京大学完成。选取8周龄雄性SD大鼠50只随机分为5组:安静组(不训练);急性运动后即刻组(不训练,处死前进行急性力竭性跑台运动);急性运动后24h组(不训练,处死前一天进行急性力竭性跑台运动);耐力训练+急性运动后即刻组(实施耐力训练方案,最后进行急性力竭性跑台运动,并在运动后即刻处死);耐力训练+急性运动后24h组(实施耐力训练方案,最后进行急性力竭性跑台运动,并在运动后的24小时处死);每组10只。耐力训练方案1次/d,6d/周。跑台速度由开始的10m/min逐渐增加到第4周30m/min,运动时间由30min/d增加到40min/d。急性力竭性跑台运动方案速度为28m/min,以动物不能坚持负荷跑速,滞跑道的后1/3处达3次以上,刺激驱赶无效(10s)为力竭标准。断头处死分离出纹状体、中脑及下丘脑,经处理后采用高效液相色谱-电化学检测法测定多巴胺、去甲肾上腺素及5-羟色胺含量。结果:50只大鼠均完成设计方案的实验,全部进入结果分析。①急性运动后即刻组纹状体多巴胺含量显著高于安静组,差异有显著性。急性运动后24h组中脑内多巴胺含量显著性低于急性运动后即刻组,差异有显著性。②急性运动后24h组和耐力训练+急性运动后24h组纹状体去甲肾上腺素含量均显著性高于安静组,差异有显著性。耐力训练+急性运动后即刻组中脑去甲肾上腺素含量显著性低于急性运动后即刻组,差异有显著性。各组间下丘脑去甲肾上腺素含量差异无显著性。③急性运动后即刻组纹状体5-羟色胺含量显著性高于安静组,差异有显著性。各组间中脑5-羟色胺含量差异均无显著性。各组间下丘脑5-羟色胺含量差异无显著性。结论:大鼠耐力训练可能使恢复期多巴胺的合成和/或重摄取能力增强,纹状体和中脑去甲肾上腺素基础值适应增高,减少运动时纹状体和中脑5-羟色胺含量的升高,维持运动时中枢机能的稳定。

AIM： To analyze responses of monoamine neurotransmitters in different brain regions to exhaustion treadmill running with or without prior endurance training. METHODS： The experiments were done from July 2002 to July 2003 in Nanjing Institute of Physical Education and Nanjing University. 50 male Sprague-Dawley rats of 8 weeks old were dived into 5 groups randomly with 10 rats in each group＂ sedentary group （without training）, right after acute exercise group （without training, sacrificed right after acute exhaustion treadmill running）, 24 hours after acute exercise group （without training, sacrificed 24 hours later after acute exhaustion treadmill running）, right after acute exercise with training group （performance endurance training program, rats were sacrificed right after acute exhaustion treadmill running ）, 24 hours after acute exercise with training group （performance endurance training program, rats were sacrificed 24 hours after acute exhaustion treadmill running）. Endurance training program： treadmill running training, once each a day, each a week had a day rest. Speed from 10 m per minute at the first week to 30 m per minute at the 4^th week. Time from 30 minutes per day at the first week to 40 minutes per day at the 4^th week. Acute exercise were exhaustion treadmill running with speed of 28 m per minute. The exhaustion standard was the rat could not keep the speed and stagnant stay in the 1/3 back part of the treadmill even with electricity stimulation for 10 s more than 3 times. Rats were sacrificed with decollation. Striatum, midbrain and hypothalamus of the brain were separated. High-performance liquid chromatography with electrochemical detection was used to determine the levels of dopamine, norepinephrine and 5-hydroxytryptamine （5-HT）. RESULTS： All the 50 rats finished the experiments and entered the analysis of results. ①Dopamine in striatum of the right after acute exercise group was significantly higher than in the the sedentary group. Dopamine in midbrain of the 24 hours after acute exercise group was significantly lower than in the right after acute exercise group. ②N orepinphrine in striatum of the 24 hours after acute exercise group and the 24 hours after acute exercise with training group both significantly higher than in the sedentary group. The concentrations of norepinephrine in the midbrain of the right after acute exercise with training group was significantly lower than in the right after acute exercise group. There were no significantly differences with norepinephrine levels in hypothalamus of each group. ③The levels of 5-HT in striatum of the right after acute exercise group were significantly higher than in the sedentary group. There were no significantly differences with 5-HT levels in both hypothalamus and midbrain of each group. CONCLUSION： Endurance treadmill training may enhance dopamine levels with dopamine synthesis and/or re-uptake. It may also improve norepinephrine basic levels and less higher 5-hydroxytryptamine in striatum and midbrain. These changes may helpful to the stabilization of central nerves system in exercise.