磷酸肌酸补充调节力竭小鼠中枢单胺类神经递质代谢

Effect of Phosphocreatine Supplement on Monoamine Neurotransmitter of Brain in Exhausted Exercise Mice

目的:探讨外源性磷酸肌酸补充对力竭运动时中枢单胺类神经递质代谢的影响。方法:4月龄48只C57/BL小鼠(雌雄不限),1周适应性游泳训练后,随机分为安静对照组(SC)、一次性游泳力竭组(SE)和磷酸肌酸补充游泳力竭组(CE)。磷酸肌酸补充组实验前30 min腹腔注射磷酸肌酸钠(500 mg/kg),SE组注射生理盐水阴性对照。力竭游泳结束即刻取材皮层、海马、下丘脑、纹状体、脑干和小脑6个脑区。脑组织取材即刻高功率微波灭活糖原合成与分解酶。高效液相色谱法测定各脑区去甲肾上腺素(NE)、5羟色胺(5-HT)及其代谢产物5-羟吲哚乙酸(5-HIAA)、多巴胺(DA)及其代谢产物双羟苯乙酸(DOPAC)含量。结果:1)磷酸肌酸补充明显延长游泳至力竭的时间;2)力竭时皮层、海马和脑干NE和DA增加,下丘脑NE和DA下降,海马和脑干DA代谢增加明显。各脑区5-HT及其代谢力竭时均增加。磷酸肌酸补充对NE和5-HT力竭时变化影响不大,但增加皮层及下丘脑DA含量,使其具有较高的DA/5-HT比值。结论:磷酸肌酸补充延长力竭时间的作用机制之一是调节皮层和下丘脑单胺类神经递质的代谢,使其具有较高的DA/5-HT比值。

Objective ： This paper explored the effect of phosphocreatine supplement on monoamine neurotransmitter of brain in exhausted exercise mice. Methods： Forty-eight C57/BL mice were randomly divided into the sedentary control group （SC） , exhausted swimming group （SE） and phosphocreatine supplemented exhausted swimming group （CE）. The intraperitoneal injection of phosphocreatine was 30 minutes before swimming in CE group, while the injection of saline solution was in SE group as a placebo. After exhaustive swimming, the cortex, hippocampus, hypothalamus, striatum, brainstem and cerebellum were collected immediately at 0℃ and inactived tissue enzymes by using high-power microwave irradiation. The brain monoamines levels, norepinephrine （NE） , 5 - hydroxytryptamine （5 - HT）, 5 - hydroxyindoleacetie acid （5 - HIAA）, dobaamine （ DA ） , and dihydroxyphenylaeetic acid （DOPAC）, were measured with high-performance liquid chromatography （HPLC）. Results： 1 ） The endurance performance in CE group was significantly prolonged compared with SE group; 2） tn exhaustive group, the concentrations of NE and DA in cerebral cortex, hippocampus and brainstem were significantly increased com- pared with SC group, while NE and DA levels in the hypothalamus were decreased significantly. The level of 5 - HT in all six brain loci were significantly increased in SE group than in SC group. The phosphoereatine supplement had no effect on NE and 5 - HT, but the level of DA in the cerebral cortex, hippocampus and brainstem were significantly increased after phosphoereatine supplement, the ratio of DA/5 - HT in CE group was higherthan in SC group. Conclusion ： The mechanism of prolonged exercise endurance by phosphocreatine supplement is that it can regulate the metabolism of monoamine neurotransmitter in cerebral cortex and hypothalamus and increase DA/5 -HT ratio.