补充谷氨酰胺对过度训练大鼠腹膜巨噬细胞IGF-1和MGF基因表达的影响

目的:了解补充谷氨酰胺对过度训练大鼠腹膜巨噬细胞胰岛素样生长因子1(IGF-1)和机械生长因子(MGF)基因表达的影响。方法:8周龄健康雄性Wistar大鼠40只,随机分为安静对照组(C)、过度训练组(E)、过度训练补充谷氨酰胺组(EG)。后两组根据取材时间不同分为2组:运动后36 h取材组(E1、EG1),运动后7天取材组(E2、EG2)。总计5组,每组8只,除C组外,其他4组进行11周递增负荷跑台训练。EG组从第5周开始至第8周灌胃补充谷氨酰胺(0.8 g/kg/d),以后几周加至饮用水补充,剂量逐周加大到1.1 g/kg/d。断头处死大鼠并分离纯化腹膜巨噬细胞,采用荧光定量PCR技术测定IGF-1和MGF基因表达。结果:安静状态下巨噬细胞即可表达IGF-1和MGF。11周过度训练后36 h,巨噬细胞IGF-1、MGF表达量显著增加,分别约为安静对照组的21倍和92倍(P<0.01)。EG1组IGF-1、MGF表达显著增加,分别约为安静对照组的10倍和37倍(P<0.01),但显著低于E1组(P<0.01)。停训后恢复7天,E2组、EG2组IGF-1、MGF表达量分别与E1组、EG1组相比均显著下降(P<0.01),但与C组相比差异无统计学意义。结论:静息态巨噬细胞可表达IGF-1和MGF;过度训练可增强巨噬细胞IGF-1和MGF表达,MGF表达对运动应激更敏感;补充谷氨酰胺可部分抑制巨噬细胞IGF-1和MGF对过度训练的应答。     

Persistent fatigue in young athletes: measuring the clinical course and identifying variables affecting clinical recovery

The objective of this paper is to measure the clinical course (months) in young athletes with persistent fatigue and to identify any covariates affecting the duration of recovery. This was a prospective longitudinal study of 68 athletes; 87% were elite (42 males, 26 females), aged 20.5±3.74 years (SD), who presented with the symptom of persistent fatigue. The collective duration to full clinical recovery was estimated using Kaplan–Meier product–limit curves, and covariates associated with prolonging recovery were identified from Cox proportional hazard models. The median recovery was 5 months (range 1–60 months). The range of presenting symptom duration was 0.5–36 months. The covariates identified were an increased duration of presenting symptoms [hazard ratio (HR), 1.06; 95% confidence interval (CI), 1.02–1.12; P=0.005] and the response of serum cortisol concentration to a standard exercise challenge (HR, 1.92; 95% CI, 1.09–3.38; P=0.03). Delay in recovery was not associated with categories of fatigue that included medical, training‐related diagnoses, or other causes. In conclusion, the fatigued athlete represents a significant clinical problem with a median recovery of 5 months, whose collective clinical course to recovery can be estimated by Kaplan–Meier curves and appears to be a continuum.     

过度训练致大鼠心肌和肾组织细胞凋亡及山莨菪碱干预的影响

目的 同步研究过度训练致心肌和肾组织细胞凋亡及山莨菪碱干预的影响.方法 采用大鼠游泳至力竭方式建立过度训练模型,将大鼠随机分为对照组、力竭组及山莨菪碱组,力竭组又根据力竭后恢复时间分为力竭即刻组、力竭后6h组和力竭后24h组;山莨菪碱组于力竭运动前腹腔注射山莨菪碱10mg/kg,分为山莨菪碱干预后6h组和山莨菪碱干预后24h组.用TUNEL法、图像分析仪及流式细胞术检测各组大鼠心肌和肾组织细胞凋亡情况.结果 力竭即刻组大鼠心肌细胞凋亡较对照组增多(P＜0.05),力竭后6h组心肌细胞凋亡更为明显(P＜0.05),力竭后24h组心肌细胞凋亡明显减少,但仍明显高于对照组(P＜0.05);力竭即刻、6h、24h组大鼠肾组织细胞凋亡逐渐增多,与对照组比较,差异显著(P＜0.05).山莨菪碱干预后6h组和山莨菪碱干预后24h组心肌和肾组织凋亡细胞数较力竭同时间组明显减少(P＜0.05).结论 心肌和肾组织细胞凋亡是过度训练致心肌和肾脏损伤的细胞学基础;心肌损伤比肾损伤恢复快;山莨菪碱可通过抑制心肌和肾组织细胞的过度凋亡,对心、肾损伤起到明显的防治作用.     

过度训练的病理生理及康复 Ⅰ.大鼠过度训练模型的建立

实验表明,运用大鼠跑台运动,以心电图、体重、饮食量、精神状况、毛发脱落、尿蛋白、血清睾酮、皮质醇等为监测指标建立大鼠过度训练模型的方法是可行的。本文并首次模拟出大鼠运动性心律失常心电图。     

Cingulate cortical and anterior thalamic neuronal correlates of the overtraining reversal effect in rabbits

Multiple-unit activity of the cingulate cortex and the anteroventral (AV) nucleus of the thalamus in rabbits was recorded during reversal training, following differential conditioning of a locomotory (wheel rotation) avoidance response. The CS+ and CS? were pure tones (1 or 8 kHz) and the UCS was a footshock delivered through the grid floor of the wheel. One group of the rabbits received original training to a criterion followed immediately by reversal training. A second group received training to criterion followed by additional training sessions (overtraining), prior to reversal training. The results indicated that the overtraining reversal effect (ORE) occurred. That is, the overtrained subjects acquired the reverse discrimination in significantly fewer sessions than the non-overtrained subjects. The overall (non-discriminative) neuronal reactivity in all cingulate cortical laminae was reduced by overtraining, whereas the overall reactivity of the AV thalamus was enhanced. In addition, the non-overtrained subjects manifested a discriminative neuronal response appropriate to the original task (i.e. a greater response to the CS? than to the CS+ for reversal training), throughout the precriterial sessions of reversal training. This persistent ‘original habit effect’ occurred only at brief latencies (20–30 msec) after CS onset, and only in the deep cortical laminae (V–VI). The neuronal activity of the superficial laminae (I–IV) in non-overtrained subjects underwent a transition, in parallel with the behavior, from a discriminative response appropriate to the original task to one appropriate to the reversal task. No significant training-related changes were seen at any cortical depth in the overtrained subjects. Presentation of non-contingent footshocks during two sessions of reversal training following criterion re-enhanced the overall reactivity and the brief-latency discriminative neuronal response appropriate to the original task, which had undergone decline during reversal training, in the deep cortical laminae of the non-overtrained subjects. The enhanced overall reactivity and the discriminative activity in the superficial laminae of non-overtrained subjects had not declined during reversal training and were not altered by the non-contingent footshocks. The implications of these data are discussed in regard to the neural causation of the ORE.     

氧化应激反应在过度训练致急性肾损伤中的作用及山莨菪碱、旋覆花素、苦碟子的影响

目的:过度训练可引起急性肾损伤(OTIAKI),为了解氧化应激反应在过度训练致急性肾损伤中的作用,本文研究了过度训练大鼠血清及肾组织SOD和MDA的改变,观察了山莨菪碱、旋覆花素、苦碟子对上述变化的影响.方法:将80只雄性Wistar大鼠随机分为安静对照组(CN)、力竭运动组(ES)、山莨菪碱干预组(AD)、旋覆花素干预组(IB)、苦碟子干预组(IS).采用大鼠游泳至力竭建立过度训练致急性肾损伤模型.采用黄嘌呤氧化酶法检测血清和.肾组织SOD和MDA的改变.结果:力竭后即刻和力竭后6h大鼠血清和肾组织SOD明显降低(P<0.05),MDA明显升高(P<0.05);血清SOD和MDA两个指标于力竭后24h恢复达到对照组水平,肾组织SOD和MDA与力竭后6h比较均有所恢复,但未达到对照组水平.于力竭后6h,山莨菪碱、旋覆花素及苦碟子三种药物对过度训练引起的大鼠血清和肾组织SOD活性的降低和MDA含量的增高均具有不同程度的逆转作用;于力竭后24h,三种药物组大鼠血清和肾组织SOD和MDA均恢复到对照组水平.结论:氧化应激反应主要参与力竭后早期引起的肾损伤过程,山莨菪碱、旋覆花素及苦碟子在OTIAKI早期可通过抗氧化应激反应来发挥肾脏保护作用.     

过度训练对大鼠血清CK、LDH、SOD、SDH活性及UMb含量影响的研究

对游泳过度训练的SD大鼠血清肌酸激酶(CK)、乳酸脱氢酶(LDH)、琥珀酸脱氢酶(SDH)、超氧化物歧化酶(SOD)活性及尿肌红蛋白(UMb)的含量进行了测试分析。结果表明,一般运动训练组血清CK、LDH、SOD、SDH活性较对照组分别升高了16.31%(P＜0.01）、19.11%(P＜0.001）、51.14%(P＜0.01）、53.20%(P＜0.001）;过度训练组上述指标分别较对照组升高了55.43%、59.21%、99.90%和104. 00%（P值均小于0.001）。本文提示,一般运动训练可影响机体细胞供能代谢及细胞膜系统功能状态,过度训练可导致骨骼肌等器官发生运动性损伤。     

A new overtraining protocol for mice based on downhill running sessions

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Plasticity in striatopallidal projection neurons mediates the acquisition of habitual actions

In instrumental conditioning, newly acquired actions are generally goal‐directed and are mediated by the relationship between the action and its consequences or outcome. With continued training, however, the performance of such actions can become automatic, reflexive or habitual and under the control of antecedent stimuli rather than their consequences. Recent evidence suggests that habit learning is mediated by plasticity in the dorsolateral striatum (DLS). To date, however, no direct evidence of learning‐related plasticity associated with overtraining has been reported in this region, nor is it known whether, or which, specific cell types are involved in this learning process. The striatum is primarily composed of two classes of spiny projection neurons, the striatonigral and striatopallidal spiny projection neurons, which express dopamine D1 and D2 receptors, and control direct and indirect pathways, respectively. Here we found evidence of a post‐synaptic depression in DLS striatopallidal projecting neurons in the indirect pathway during habit learning in mice. Moreover, this training‐induced depression occluded post‐synaptic depression induced by co‐activation of D2 receptors and transient receptor potential vanilloid 1 (TRPV1) channels, implying that this pathway is involved in habit learning. This hypothesis was further tested by disrupting this signal pathway by knocking out TRPV1 channels, resulting in compromised habit learning. Our findings suggest that post‐synaptic plasticity at D2 neurons in the DLS mediates habit learning and, by implicating an interaction between the D2 receptor and TRPV1 channel activity, provide a potential drug target for influencing habitual action control.