力竭运动过程中大鼠苍白球内侧部对皮层的调控作用

目的:探讨力竭运动中大鼠苍白球内侧部对皮层的调控作用。方法:采用皮层脑电(ECoG)及局部场电(LFPs)同步记录技术,动态观察一次性力竭运动中大鼠皮层辅助运动区、苍白球内侧部神经元电活动变化规律。结果:运动开始阶段,大鼠能够自主跟随跑台进行运动,持续约43 min(43±11.8 min)后,大鼠自主运动能力明显降低,此时,皮层神经元功率谱重心频率显著降低(P<0.01),提示神经元兴奋性下降,而苍白球内侧部神经元功率谱重心频率显著升高(P<0.01),提示兴奋性增强;此时给予大鼠一定的外部刺激,大鼠仍可继续运动一段时间直至力竭,皮层神经元功率谱重心频率降至最低(P<0.01),而苍白球内侧部神经元功率谱重心频率达到最高(P<0.01)。力竭运动过程中,苍白球内侧部局部场电活动与皮层脑电活动呈相反变化趋势,且不同阶段两区域神经元在0~30Hz范围内均显著相干。结论:力竭运动过程中苍白球内侧部神经元兴奋性增强经丘脑中继后对皮层神经元产生去兴奋作用,是导致疲劳及运动能力下降的重要因素之一,提示苍白球内侧部-丘脑-皮层通路在运动疲劳产生过程中起重要调控作用。     

纹状体A_(2A)R和D_2DR对大鼠力竭运动过程中苍白球GABA和Glu释放的调控研究

目的:探讨纹状体腺苷A2A受体(A2AR)和多巴胺D2受体(D2DR)对大鼠力竭运动过程中苍白球胞外γ-氨基丁酸(GABA)与谷氨酸(Glu)释放的调控作用。方法:采用纹状体微量灌注和活体微透析-高效液相联用技术,实时、在线观察大鼠在一次力竭运动过程中苍白球细胞外液中GABA和Glu水平的动态变化规律,以及D2DR激动剂(喹吡罗,Quinpirole)和A2AR拮抗剂(SCH58261)对其影响,结合运动能力探讨D2DR和A2AR对疲劳的调控作用机制。结果:大鼠3级递增负荷跑台运动至力竭过程中,苍白球胞外Glu和GABA呈增高趋势,Glu/GABA呈降低趋势,在运动开始后45min至力竭各点Glu和GABA均显著高于安静水平(P<0.05),Glu/GABA显著低于安静水平(P<0.05),力竭后恢复90 min时Glu和GABA逐渐下降至安静水平,Glu/GABA逐渐恢复至安静水平;SCH58261和Quinpirole分别经纹状体灌注后,力竭运动过程中苍白球胞外Glu和GABA变化明显下降,大鼠自主运动期(疲劳初期)时间延长,大鼠跑台运动至力竭时间显著增加(P<0.05)。结论:在一次力竭运动过程中,大鼠苍白球神经元胞外Glu、GABA浓度及Glu/GABA均具有明显的阶段性特征,推测可能是力竭过程中大鼠运动能力呈现阶段性变化特征的机制之一;大鼠在力竭时,苍白球胞外Glu、GABA升高但Glu/GABA下降,推测力竭时大鼠苍白球神经元的兴奋性下降;SCH58261和Quinpirole经纹状体微量注射后,苍白球胞外Glu和GABA变化明显下降,大鼠自主运动期(疲劳初期)时间延长,大鼠跑台运动至力竭时间显著增加,推测可能是因为SCH58261和Quinpirole分别经各自作用机制干预了纹状体投向苍白球的GABA能传递而影响了间接通路对皮层的调控,最后达到延缓疲劳的作用。     

不同力竭运动对大鼠纹状体背外侧神经元电活动的影响及调节机制研究

目的：探讨一次和重复力竭运动对纹状体背外侧神经元电活动的影响及可能的调节机制。方法：8周龄健康雄性Wistar大鼠，随机分为安静对照组（CG）、一次力竭运动组（EG）、7天重复力竭运动组（REG），每组24只，其中6只做电生理实验。采用在体多通道电生理技术记录大鼠在清醒安静状态下，一次力竭运动和7天重复力竭运动后大鼠纹状体背外侧的神经元放电活动；采用免疫荧光双染技术观察各组大鼠纹状体背外侧小青蛋白（Parvalbumin,PV）及NMDAR2B阳性神经元的表达。结果：（1）与安静状态相比，一次力竭运动后大鼠纹状体背外侧中等多棘神经元（medium spiny neuron,MSN）放电频率未发生显著改变（P>0.05），而重复力竭运动后MSN放电频率明显升高（P<0.01）;(2)一次和重复力竭运动后大鼠纹状体背外侧局部场电位γ频段的功率谱密度均较安静状态有明显增加（P<0.01），重复力竭运动后增加更为明显，且与一次力竭运动后相比有明显差异（P<0.05）;(3)一次和重复力竭运动组大鼠纹状体背外侧PV阳性神经元表达较安静对照组有显著增加（P<0.01）...     

力竭运动过程中大鼠纹状体葡萄糖/乳酸代谢的实时观察

目的:通过实时观察一次性力竭运动过程中大鼠纹状体葡萄糖和乳酸浓度的动态变化规律,揭示运动性中枢疲劳形成过程中脑能量代谢的特征。方法:8周龄雄性Wistar大鼠20只分为两组,纹状体葡萄糖、乳酸测定组(第1组)和外周血葡萄糖、乳酸测定组(第2组),每组10只。采用微透析-电化学联用的活体检测技术,实时监测大鼠(第1组)在一次性力竭运动过程中纹状体细胞外液中葡萄糖和乳酸的代谢变化,并从尾静脉采血动态监测大鼠(第2组)外周血液中葡萄糖和乳酸浓度的变化。结果:(1)与安静状态相比,运动初期大鼠纹状体胞外乳酸浓度显著升高(P<0.05),运动后期直至恢复期均显著降低(P<0.05,P<0.01);而胞外葡萄糖浓度在运动初期无明显变化,在运动后期开始下降,甚至在恢复期的90分钟内仍显著低于安静水平(P<0.05,P<0.01)。(2)大鼠外周血糖浓度随着运动时间的延长而显著降低,在运动力竭以及恢复期血糖水平均显著低于安静水平(P<0.05,P<0.01);大鼠血乳酸浓度在力竭运动过程中显著高于安静时水平(P<0.05),而在运动结束后即迅速恢复至安静时水平。结论:力竭运动过程中,持续的外周低血糖导致脑对于葡萄糖摄取不足,出现脑葡萄糖和乳酸浓度降低,中枢能量物质葡萄糖和乳酸代谢的显著降低可能是产生运动性中枢疲劳的一个重要的神经生物学机制。     

力竭运动前后活体大鼠纹状体谷氨酸和γ-氨基丁酸水平的动态变化

目的:观察一次性力竭运动过程中大鼠纹状体内神经递质谷氨酸(Glu)和γ-氨基丁酸(GABA)含量及其比值的动态变化,探讨运动疲劳后纹状体神经元电活动改变的可能机制.方法:8周龄雄性Wistar大鼠8只,通过手术预先将透析套管定植入左侧纹状体(P:0.2,L:3,H:3.2).采用活体微透析与高效液相色谱(HPLC)检测...     

力竭运动大鼠丘脑底核mGluR5/GABA-ARα1表达及MPEP干预对皮层运动区兴奋性的影响

目的:探讨力竭运动影响丘脑底核(STN)神经元电活动改变的可能机制。方法:雄性Wistar大鼠随机分为安静对照组(CG)、力竭即刻组(FG)、恢复90min组(RG)和受体拮抗剂干预组、人工脑脊液对照组,每组均为6只,分别用于免疫组化和干预实验。采用递增负荷进行一次性力竭跑台运动。采用免疫组化技术对一次性力竭运动前、后及恢复过程中大鼠STNmGluR5及GABA-ARα1表达进行观察;并通过STN微量注射mGluR5拮抗剂(MPEP),观察大鼠一次性力竭运动过程中皮层兴奋性及运动能力的变化。结果:力竭即刻组大鼠与安静对照组相比STNmGluR5、GABA-ARα1表达水平差异不显著,恢复90min组大鼠STNmGluR5表达显著高于安静对照组,而GABA-ARα1表达无显著改变。MPEP干预组大鼠与人工脑脊液对照组相比ECoG重心频率曲线的第一波谷出现时间推迟约30min,且运动至力竭的时间明显延长。结论:运动引起STNmGluR5表达改变是导致大鼠STN神经元电活动改变的因素之一;MPEP具有抑制大鼠STN神经元电活动的过分增强并改善运动能力的作用。     

力竭运动过程中大鼠皮层–基底神经节通路α/β同步振荡的起源和传递路径

目的:探讨一次力竭运动过程中皮层–基底神经节通路振荡电活动变化特征、同步振荡电活动的起源和传递路径以及运动疲劳产生的振荡电活动中枢调控机制.方法:以健康4周龄雄性Wistar大鼠为研究对象,采用在体多通道神经电信号记录技术,对一次性力竭运动过程中大鼠皮层(M1)和基底神经节(Str、GPe、SNr和STN)的局部场电位...     

运动疲劳对大鼠新纹状体神经元电活动的影响

目的:观察运动疲劳大鼠新纹状体神经元自发放电情况,探讨运动疲劳产生的中枢机制.方法:采用胞外玻璃微电极技术,对运动疲劳前后大鼠新纹状体神经元自发放电频率、神经元动作电位时程及动作电位发放形式进行记录,并对放电神经元的分布规律进行分析.结果:(1)在记录到的运动疲劳组大鼠新纹状体神经元中,19%自发放电频率>10Hz,而对照组仅有6%,两组相比存在显著差异(P<0.05);(2)运动疲劳组大鼠新纹状体神经元除观察到规则单脉冲放电、不规则单脉冲放电、单脉冲与爆发式并存的放电形式外,还观察到规则爆发式放电,其串间隔集中在140～210ms;(3)运动疲劳组高频自发放电的神经元主要集中在新纹状体的外侧深部区域. 结论:运动疲劳后新纹状体神经元自发放电频率发生改变,高频放电神经元数量明显增加.结果提示运动疲劳后神经元放电形式发生改变,可能与神经元胞内钙离子浓度升高相关.     

运动疲劳对大鼠纹状体神经元GLUT_3 mRNA和蛋白表达的影响

目的:探讨运动疲劳后大鼠纹状体神经元GLUT_3 mRNA和蛋白表达的适应性变化。方法:Wi-star大鼠40只,任选10只为正常对照组,其余采用多级递增负荷跑台运动建立运动疲劳模型,留其成功的20只为疲劳组;测试两组大鼠血糖、血乳酸、尿素氮及血清胰岛素含量,采用逆转录-聚合酶链反应(RT-PCR)法测定纹状体神经元GLUT_3 mRNA的表达,运用免疫组化法观测该部神经元GLUT_3的蛋白表达情况。结果:力竭后即刻,实验组大鼠血糖、血清胰岛素含量均显著低于对照组大鼠(P<0.05),而血乳酸及尿素氮水平显著高于对照组大鼠(P<0.05),纹状体神经元GLUT_3 mRNA及蛋白的表达均较对照组大鼠显著上调(P<0.05)。结论:运动疲劳后大鼠能量基本耗竭,迫使机体以非胰岛素依赖方式上调纹状体神经元GLUT_3 mRNA和蛋白表达水平来应激,以此延搁由能量衰竭所引起的级联反应,从而形成一种适应性保护反应来减缓运动性疲劳的发生。     

力竭运动后大鼠海马CA1区自由基、下丘脑GABA及HPA轴的动态变化

目的:探讨运动性疲劳时神经内分泌系统的中枢调控机制。方法:50只SD大鼠随机分为安静对照组和力竭性游泳运动组,力竭组大鼠进行一次性力竭游泳运动,运动后即刻、1h、3h和24h断头取材。用放免法测定下丘脑促肾上腺激素释放激素(CRH)、血清肾上腺皮质激素(ACTH)和血清皮质酮(C);DNS-Cl荧光光度法测定下丘脑γ-氨基丁酸(GABA)含量;顺磁共振波谱法测定PBN自旋捕获剂捕获的海马CA1区自由基含量。结果:(1)力竭运动后即刻和恢复1小时组大鼠下丘脑CRH显著低于安静对照组;运动后即刻组血清ACTH浓度低于安静对照组,运动后1小时和3小时组高于安静对照组,但均无显著性差异;运动后即刻组血清C明显高于安静对照组。(2)与安静对照组相比,力竭运动后即刻、1小时和3小时组大鼠下丘脑GABA含量均显著升高。(3)与安静对照组相比,运动后即刻组大鼠海马CA1区自由基信号强度显著增强。(4)下丘脑GABA含量与下丘脑CRH呈显著负相关;海马CA1区自由基信号强度与下丘脑GABA含量呈显著正相关;海马CA1区自由基信号强度与下丘脑CRH呈显著负相关。结论:(1)下丘脑GABA可能通过直接作用于CRH神经元参与抑制运动应激时下丘脑-垂体-肾上腺皮质(HPA)轴的过度激活,并将运动疲劳时中枢的抑制状态传递到外周,使机体免受HPA轴过度激活带来的损伤。(2)力竭性运动时海马CA1区神经元自由基的增加使兴奋性增强,并可能通过Glu-GABA突触联系间接对HPA轴活性进行抑制。     

中药复方“体复康”对运动性疲劳大鼠脑组织神经肽Y动态变化影响的研究

为了从脑组织神经肽Ｙ水平探索运动性疲劳产生及药物调节的机理，采用ＡＢＣ免疫组织化学法结合图象分析，观察中药复方“体复康”对运动性疲劳大鼠不同脑区神经肽Ｙ的动态变化。结果显示：一定强度（速度由１５ｍ／ｍｉｎ递增至３５ｍ／ｍｉｎ，运动时间为２０至２５ｍｉｎ／ｄ）长期（共７周）运动的大鼠，安静状态下在丘脑室旁核（ＰＶ）、下丘脑背内侧核（ＤＭ）、下丘脑腹内侧核（ＶＭＨ）等核团ＮＰＹ无显著性变化；在此基础上的未次急性运动结束后３小时ＮＰＹ变化尤为明显。中药复方“体复康”对于慢性运动应激过程中ＮＰＹ的调节作用不明显，在急性运动应激中，中药复方对ＮＰＹ的调节在运动结束后３小时尤为明显，且呈双向调节，即在ＰＶ、ＤＭ核团下调，而在ＶＭＨ核团上调，结论：神经肽Ｙ在运动性疲劳大鼠不同脑区呈现不同的动态变化趋势，中药复方“体复康”对ＮＰＹ有双向调节作用。     

Direct vs. indirect blood pressure measurement at peak anaerobic exercise.

The present study compared the direct intra-arterial method with the indirect conventional sphygmomanometer during all-out anaerobic exercise, in young healthy subjects. Systolic and diastolic blood pressures were measured by intraarterial means and by auscultation. Fourteen young healthy males (23+/-2 yrs) were measured at rest and during all-out anaerobic exercise. Comparisons were made with simultaneously determined intra-arterial catheter and auscultation measurements. The data suggest that indirect systolic pressure is highly correlated with the direct method at rest (r = 0.684), with mean of 107+/-7 and 101+/-6 mmHg, respectively, and during all-out anaerobic exercise (r = 0.87), with mean of 197+/-11 and 191+/-9 mmHg, respectively. Indirect diastolic blood pressure correlates well with intra-arterial at rest (r = 0.62), with mean of 84+/-11 and 77+/-9 mmHg, respectively. However, during all-out anaerobic exercise, the correlation coefficient between the direct and the indirect methods was low (r = 0.36), with mean of 101+/-12 and 103+/-9 mmHg, respectively. These results suggest that when utilizing an all-out anaerobic exercise, the indirect method is not valid for assessment of diastolic pressure. In addition, although the anaerobic test is a dynamic type of exercise, its blood pressure responses for both direct and indirect methods were similar to those seen during isometric exercise.     

运动引起的脑与血浆亮脑啡肽变化的初步观察

<正> 脑啡肽是近年发现的一类神经调制物质—呐啡肽的一种,由中间神经元释放后作用在突触部位,在心血管、呼吸、内分泌及运动等多方面显示生理功能。脑啡肽还在肾上腺髓质嗜铬细胞内与儿茶酚胺共存并共同释放入     

The effects of rest interval length and training on quadriceps femoris muscle. Part I: knee extensor torque and muscle fatigue

AIM: The purpose of this study was to examine the effects of rest interval on quadriceps femoris (QF) muscle strength and fatigue during short-term, high-intensity training. METHODS: Fifteen healthy males were assessed for isokinetic QF strength, via peak torque (PT), work (WK) and power (PW), at a pre-set angular velocity of 180 deg x s(-1). Quadriceps femoris muscle fatigue was evaluated as the decline in isokinetic work and power (slope) across 30 maximal concentric contractions. Subjects were randomly assigned to 1 of 3 groups: Group 1 (short rest interval), Group 2 (long rest interval), and Group 3 (control-no training). Subjects in Group 1 received a rest period of 40 s in between exercise sets corresponding to a 2:1 rest:work ratio. Subjects in Group 2 received a rest period of 160 s corresponding to an 8:1 rest:work ratio. Groups 1 and 2 performed isokinetic knee extension contractions at 180 deg x s(-1) 2 days per week for 6 weeks. RESULTS: The results demonstrated a significant increase in QF muscle PT across the 6 week training period in the long rest interval group, and no significant changes in the short rest interval and control groups. Quadriceps femoris muscle work and power were observed to not change significantly across the training period in all 3 groups. The reduction in QF muscle work across the single set of 30 repetitions was observed to decrease significantly in the control group across the 6 week duration; no other significant changes in QF muscle fatigue for work and power were observed. CONCLUSION: The major findings of this study suggests that the possibility of different physiological mechanisms of adaptation exist for QF muscle peak torque, work and power, while changes in muscle fatigue resistance may be present when assessed across multiple, rather than a single, bouts of activity.     

一次大强度运动对大鼠骨骼肌泛素蛋白酶体途径基因表达及蛋白质降解的影响

目的:观察1次大强度运动后骨骼肌泛素蛋白酶体途径组成成分基因表达的变化,探讨该途径在运动后骨骼肌蛋白质降解中的作用。方法:36只雄性SD大鼠,体重190～220 g,跑台运动适应3天,休息1天,取6只为安静对照,其余大鼠进行1次1小时跑台运动(25 m/min,5%坡度)。运动0.5小时即刻、运动1小时即刻、运动后1小时、运动后2小时、运动后6小时,分别选6只大鼠取腓肠肌,用Real-Time PCR法测定泛素、MuRF1、MAFbx mRNA含量,用Western Blot法检测泛素化蛋白含量,用高效液相色谱法检测肌肉3-MH含量。结果:运动0.5、1小时即刻至运动后6小时,腓肠肌泛素mRNA含量与安静时比较无显著性差异(P>0.05)。1小时运动后1、2和6小时,腓肠肌MAFbx和MuRF1 mRNA含量较安静时显著升高(P<0.01,P<0.05)。1小时运动后6小时,腓肠肌泛素化蛋白含量显著高于安静时(P<0.01)。运动0.5小时、1小时即刻和运动后6小时,腓肠肌3-MH含量显著高于安静(P<0.01)。结论:1次大强度运动后,骨骼肌泛素蛋白酶体途径基因表达升高,骨骼肌收缩蛋白降解增加。     

Muscle fatigue during dynamic contractions assessed by new spectral indices

PURPOSE: The aim of the present study was to test the applicability and sensitivity of new electromyography (EMG) spectral indices in assessing peripheral muscle fatigue during dynamic knee-extension exercise. METHODS: Seven subjects completed 10 sets of 15 repetitions of right knee-extension exercise lifting 50% of their one-repetition maximum. Torque (T), knee-joint angle, and the interference EMG of rectus femoris muscle were recorded simultaneously. Maximal voluntary isometric contraction (MVC) was tested before and after exercise. Median spectral frequency (Fmed) and new spectral indices of muscle fatigue (FInsmk) were calculated for each repetition. RESULTS: The rate and range of FInsmk- and Fmed-relative changes against the first repetition of the corresponding set increased gradually across successive repetitions within the set, reflecting accumulation of peripheral muscle fatigue. The maximal change of FInsmk observed in the present experiment was approximately eightfold, whereas that of Fmed was only 32%. Significant between-subject variability in the range of FInsmk changes (P < 0.0001) was found, so a hierarchical cluster analysis of muscle fatigue indices was conducted. Three distinct subgroups of subjects were identified: high (N = 1, FInsmk change > 400%), medium (N = 4, 200% < FInsmk change < 400%), and low (N = 2, FInsmk change < 200%) muscle fatigability. The changes in muscle performance during (last vs first repetition peak T, P = 0.03) and after (post- vs preexercise MVC, P = 0.012) exercise were significantly different between clusters (one-way ANOVA). The rate of fatigue development was also significantly different between clusters (linear regression analysis of Fmed and FInsmk changes). CONCLUSIONS: The new spectral indices are a valid and reliable tool for assessment of muscle fatigability irrespective of EMG signal variability caused by dynamic muscle contractions, and these indices are more sensitive than those traditionally used.