反复离心运动对大鼠骨骼肌损伤和蛋白质降解机制的影响

目的:探讨连续离心运动训练对骨骼肌中Calpain和Ubiquitin含量的影响及其与骨骼肌损伤之间的关系;方法:雄性SD大鼠29只随机分为对照组、离心训练后即刻组、24 h组和7天组.训练组大鼠连续进行7天的下坡跑运动,分别在末次训练后即刻,24 h和第7天取股四头肌,测定股四头肌的超微结构、血清LDH和CK活性以及骨骼肌中Calpaim-1、Calpain-2和Ubiquitin含量;结果:1)7天离心训练后即刻和24h,股四头肌超微结构的损伤性变化呈渐进性加重,离心训练后24 h组出现明显的肌丝坏死.训练后第7天仍不能完全恢复.血清CK和LDH活性的变化与大鼠股四头肌超微结构的变化相一致.2)与对照组相比,末次训练后即刻骨骼肌中Calpain-1、Calpain-2和Ubiquitin含量均显著升高;训练后24 h,Calpain-1和Calpanin-2含量进一步升高,其中,Calpain-1显著高于对照组和训练后24 h组,Calpain-2虽显著高于对照组,但与训练后即刻组相比无显著性差异;而Ubiquitin含量显著低于训练后即刻组.训练后第7天,Calpain-1和Calpain-2含量显著低于训练后24 h组,但仍然高于对照组;而Ubiquitin含量虽高于训练后24 h组和对照组,但无显著性差异;结论:1)连续的离心运动可能对骨骼肌纤维的损伤产生一定的累加作用;2)短期连续的离心训练后,骨骼肌中Calpain和Ubiquitin的动态变化几乎与骨骼肌超微结构的动态变化相一致.离心运动训练导致骨骼肌中Calpain和Ubiquitin含量的增加,可能是导致骨骼肌累积性损伤的重要机制.     

青年男性长期离心力量训练对等长运动时心率及其变异性的影响

目的:研究健康男性大学生膝关节(屈肌和伸肌)经过长期离心训练后,在SIVC时(SIVC)心率(HR)及心率变异性(HRV)的变化.方法:将受试者分为对照组和实验组,对照组不进行力量训练,实验组进行离心训练(持续训练10周、每周3次、8～12次峰值力矩的70%～80%训练、2～4组).完成训练10周后,分别采集受试者在SWC(最大等长收缩峰值的15%、30%和40%)时的HR及HRV(频域分析中的LF和HF).结果:实验组在训练10周后离心收缩时PT显著增加(P<0.05),等长练习的持续时间显著增加(P<0.05),但训练组在训练前、后HR反应模式和HRV均无显著性差异(P>0.05).结论:离心训练增加了肌肉离心收缩力矩和肌肉等长收缩持续时间,但并没有影响植物性神经对心率自律的调控.     

下坡跑训练对大鼠血清CK、LDH的影响

采用实验对比法,观察1次和1周下坡跑训练对大鼠血清CK、LDH的影响。结果显示．1次运动后即刻,大鼠血清CK、LDH活性迅速上升,然后逐渐下降,运动后7天虽明显恢复,但仍未到达正常值;1周运动后,大鼠血清CK、LDH活性的变化趋势类似1次运动组,但各点均低于1次运动组,且7天后恢复到正常值。提示：连续离心运动可加速1次离心运动后肌肉损伤的恢复,机体对运动逐渐产生适应。     

离心运动对大鼠骨骼肌线粒体ATP酶活性及desmin表达影响的研究

目的:从细胞内线粒体Ca2+转运系统入手,探讨离心运动对大鼠骨骼肌细胞线粒体ATP酶活性及desmin表达影响,以期进一步揭示骨骼肌运动性损伤的发生机制.方法:雄性SD大鼠96只,体重304g±12g,随机分为安静对照组、运动后即刻组、运动后12h组、运动后24h组、运动后48h组、运动后72h组、运动后5d组、运动后7d组.采用一次性下坡跑训练建立运动损伤模型,取大鼠肱三头肌,部分肌肉做desmin免疫组化切片,并进行定量分析;余下肌肉差速离心提取线粒体,测定线粒体各ATP酶活性.结果:1)离心运动后大鼠骨骼肌desmin表达从运动后即刻到24h呈逐渐下降的趋势,以运动后24h下降最为明显,48h开始回升,第5d达到最高,第7d略有下降,但仍明显高于安静对照组.2)离心运动后即刻大鼠骨骼肌细胞线粒体Ca2+-ATPase、Ca2+-Mg2+-ATPase和Na+-K+-AT-Pase的活性显著下降,12h、24h酶活性有所恢复,仍然明显低于安静对照组;48h后各ATP酶结果与安静对照组均无显著差异.结论:大鼠离心运动后骨骼肌细胞线粒体ATP酶活性变化与desmin表达之间存在着某种密切相关的联系,线粒体钙调节失衡是导致骨骼肌运动损伤的一个重要原因;而离心运动后desmin表达的变化,对骨骼肌运动性损伤形态学变化的早期界定和损伤恢复程度的判断具有重要的参考价值.     

反复离心运动致骨骼肌超微结构变化的实验研究

目的 探讨反复离心运动后大鼠骨骼肌超微结构的改变.方法 雄性SD大鼠52只随机分为对照组、1次离心运动组和1周离心训练组.1次离心运动组进行1次下坡跑运动,离心训练组按照同样的强度进行7天的下坡跑训练.分别在急性运动和末次训练后即刻,24 h和第7天取股四头肌,观察股四头肌的超微结构和血清LDH、CK活性变化.结果 1次离心运动后即刻和24 h,股四头肌超微结构的损伤性变化呈渐进性加重,运动后第7天基本上可恢复到运动前水平;7次离心训练后即刻和24 h股四头肌超微结构的损伤性变化也具有相似的趋势,但训练后第7天仍未完全恢复;且在各个时段,7次离心训练组股四头肌的损伤性变化均比1次离心运动组严重.血清CK和LDH活性的变化与大鼠股四头肌超微结构的变化相一致.结论 离心运动所致的骨骼肌损伤具有一定的延迟现象,在1次离心运动后即刻,骨骼肌损伤从整体看并不严重,但在运动后24 h出现明显的损伤性变化,而运动后7天骨骼肌损伤基本上可以恢复.连续的离心运动可能导致骨骼肌纤维的损伤产生一定的累加作用.     

运动生物力学

G804.6 9902512屈肘肌连续7天离心训练做功及力矩观察=Seven days' succession of eccentric ofexercise of the flexed elbow muscle andthe observation of its moment of force[刊,中,I]/刘波,张世明,马建,虞亚民,秦雪飞∥成都体育学院学报.-1999.-25(1).-73-77图3表2参14(BJ)离心∥训练∥肌肉∥力矩∥研究用计算机采控的离心训练设备进行连续7天屈肘肌离心训练产生 DOMS,通过屈肘肌作功和力矩的动态观察,发现连续7天离心训练 DOMS产生后,肌力的恢复没有明显影响。     

重复运动对骨骼肌超微结构变化的实验研究

目的:探讨重复运动后大鼠骨骼肌超微结构的改变。方法:雄性SD大鼠72只随机分为对照组、1次离心运动组和连续1周重复运动训练组。1次离心运动组进行1次下坡跑运动,重复运动组按照同样的强度进行连续7天的下坡跑训练。分别在1次离心运动即刻、24h、48 h、72 h、120 h、168 h和第7天末次训练后即刻24 h、48 h、72 h、120 h、168 h取股四头肌。结果:1次离心运动后即刻和24 h、48 h,股四头肌超微结构的损伤性变化呈现渐进性加重,运动后第168 h基本上可恢复到运动前水平;7次离心训练后即刻和24 h股四头肌超微结构的损伤性变化也具有相似的趋势,但训练后168 h后仍未完全恢复;且在各个时段,7天离心训练组股四头肌的损伤性变化均比一次离心运动组更加严重。结论:重复运动所致的骨骼肌损伤具有一定的延迟现象,在1次离心运动后即刻,骨骼肌损伤从整体看并不严重,但在运动后24h出现明显的损伤性变化;48 h达到高点,而运动后7天骨骼肌损伤基本上可以恢复。连续的重复运动可能导致骨骼肌纤维的损伤产生一定的累加作用。     

全身震动训练对离心运动诱导的延迟性肌肉酸痛影响

目的：研究离心运动前使用全身振动训练对 DOMS 预防的影响。方法：随机对照研究,30 名专业散打运动员随机分为全身振动训练组（n=15）和对照组（n=15）。受试者：优势腿膝伸肌在功率计上完成 6 组 10 次最大等速（60 °/s）离心收缩。全身振动训练组,受试者在振动平台上进行训练,25Hz,5 mm 峰值,离心运动前膝关节 100°屈曲 60 s。对照组不进行振动训练。结果：记录运动后第 1、2、3、4、7 和 14 天的肌肉酸痛、大腿围、压痛阈,测量血清肌酸激酶的基础值和运动后第 1、2、7 天的值。与对照组相比,肌酸激酶水平较低,压痛阈和肌肉酸痛较低,DOMS 症（不顺通）状减轻（P<0.05）,但是对大腿围没有明显的影响。结论：离心运动前,全身振动训练可能通过改善肌肉功能而降低 DOMS,还需要进一步研究以确定全身振动训练组降低运动员 DOMS 的作用。     

不同离心速度训练对运动员肩关节伸肌群的肌力影响

为了研究不同离心速度训练对上肢肌肉力量的影响,通过对24名运动员肩关节伸肌群进行不同离心速度的力量训练.结果 发现离心收缩训练对改善运动员的肌肉力量有明显效果.其中3组训练前后在肌肉最大力矩、总功等方面有明显改善,特别是在以120°/s向心测试时的数据变化最显著.     

核心力量训练对跳马运动员杨佩肌力影响的研究

采用等速测力和表面肌电测试方法对杨佩核心力量训练前后的关节肌肉力量和身体动态平衡素质进行评定,得到相关指标。发现杨佩左右肩关节、髋关节、膝关节屈伸肌群向心与离心收缩的慢速(60°/s)力量经过核心力量训练后有着显著性提高(P<0.05),其快速力量(240°/s)经过核心力量训练后明显提高,但不具有显著性差异。杨佩腰背屈肌群向心收缩力量明显高于伸肌群的力量,这与其长期专项力量训练有关。腰背的慢速(60°/s)力量经过核心力量训练后有显著性提高(P<0.05)。杨佩踝关节屈伸肌群的慢速(60°/s)和快速(240°/s)力量经过核心力量训练后有一定提高,但不具有显著性差异。杨佩左右肩关节、髋关节慢速(60°/s)向心与离心收缩的峰值力矩的屈伸比值经过核心力量训练后显著提高(P<0.05),快速(240°/s)向心与离心收缩的峰值力矩的屈伸比值经过核心力量训练后明显提高,但不具有显著性差异。杨佩在不平衡板上蹲起动作受测试肌肉积分肌电(IEMG)经过核心力量训练后显著降低(P<0.05);杨佩在不平衡板上蹲起动作受测试肌肉平均功率频率(MPF)经过核心力量训练后显著提高(P<0.05),说明通过核心力量训练后其提高了动态情况下对身体重心的控制能力,核心肌群的力量以及稳定程度增加。     

血清肌酸激酶与骨骼肌损伤关系的探讨

研究目的在于对血清肌酸激酶与骨骼肌损伤之间的关系进行探讨。采用跑台一次性离心运动至力竭的动物模型,48只7周龄雌性大鼠随机分为安静对照组和运动后即刻、1、2、4和7天组,测定血清肌酸激酶活性,同时通过HE染色分析骨骼肌形态学损伤变化。结果显示血清肌酸激酶活性峰值出现在运动后即刻,运动后1天迅速下降。HE染色结果则表明离心运动后骨骼肌损伤呈现延迟性时相特点,在运动后第2天骨骼肌损伤范围达到最大。本实验表明血清肌酸激酶与骨骼肌损伤的变化趋势并不一致,血清肌酸激酶水平不能反映骨骼肌损伤。     

钙网蛋白参与钙调节对离心运动后骨骼肌微损伤的保护

目的:探讨钙网蛋白CRT参与钙调节对骨骼肌微损伤的保护作用。方法:利用离心运动至力竭模型为研究手段,40只SD大鼠随机分成安静对照组(C)、运动即刻组(E1)、运动后24小时组(E2)、运动后48小时组(E3)和运动后6天组(E4)。结果:运动后血清CK、LDH活性升高,并在24小时后达到峰值,其中E1、E2和E3组均较C组呈显著性升高(分别为P<0.01、P<0.01和P<0.05)。运动后E1组肌质网Ca2+浓度最高,其中E1和E2组均较C组呈显著升高(均为P<0.05)。运动后E2组线粒体Ca2+浓度最高,其中E1、E2和E3组均较C组呈显著升高(分别为P<0.05、P<0.01和P<0.05)。运动后E1、E2组骨骼肌中CRT的表达显著上升。结论:CRT表达在运动后的变化显示骨骼肌在运动后可能通过产生钙网蛋白来维持钙平衡,减轻骨骼肌的微损伤。     

离心力竭运动对大鼠骨骼肌肌浆网Ca^2＋-ATP酶活性的影响

目的：采用大鼠下坡跑运动损伤模型,研究离心力竭运动后不同时刻大鼠骨骼肌肌浆网Ca^2＋-ATP酶活性的变化,探讨离心力竭运动所致骨骼肌超微结构损伤机制,为科学运动训练及运动恢复提供实验和理论依据。方法：雄性SD大鼠60只随机分为6组（每组10只）：安静对照组、运动后即刻组、12h组、24h组、48h组和72h组,以速度16m/min,坡度-16°进行跑台运动,运动100min,休息5min,再运动100min,在不同时刻观察大鼠肱三头肌肌浆网Ca^2＋-ATP酶活性的变化。结果：运动后即刻肌浆网Ca^2＋-ATP酶活性与对照组相比显著下降（P〈0.01）,随后开始恢复,运动后24h接近对照组水平（P〉0.05）,运动后48h已完全恢复到对照组水平。结论：离心力竭运动后即刻大鼠肱三头肌肌浆网Ca^2＋-ATP酶活性显著下降,随后逐渐恢复,运动后24h明显恢复,至48h已完全恢复,肌浆网Ca^2＋-ATP酶活性的变化可以间接评定运动后骨骼肌的损伤。     

离心运动对大鼠骨骼肌结蛋白分布和表达的影响--对骨骼肌损伤机制的研究

方法：48只7周龄雌性SD大鼠进行一次性下坡跑至力竭，取比目鱼肌进行desmin免疫组化染色，然后光镜观察切片，并用图像分析仪对免疫染色切片进行定量分析。结果：1)离心运动后肌纤维局部desmin染色不同程度、不同范围地出现了变淡、模糊、甚至缺失，出现desmin阴性纤维；2)与对照组相比，力竭运动后即刻desmin平均光密度显著降低，在力竭后1天降到最低点，随后desmin平均光密度开始逐渐上升，到第7天，desmin阳性区域的平均光密度均显著高于对照组C。desmin阳性面积百分比和积分光密度结果变化趋势一致，离心运动组desmin阳性面积百分比低于对照组，desmin阳性面积百分最低点出现在运动后第1天。结论：1)desmin细胞骨架破坏是离心运动诱导损伤的形态学标志；2)Desmin免疫组化染色可以作为评估骨骼肌早期损伤的工具。     

Maximal-intensity isometric and dynamic exercise performance after eccentric muscle actions

A well-documented observation after eccentric exercise is a reduction in maximal voluntary force. However, little is known about the ability to maintain maximal isometric force or generate and maintain dynamic peak power. These aspects of muscle function were studied in seven participants (5 males, 2 females). Knee extensor isometric strength and rate of fatigue were assessed by a sustained 60 s maximal voluntary contraction at 80 degrees and 40 degrees knee flexion, corresponding to an optimal and a shortened muscle length, respectively. Dynamic peak power and rate of fatigue were assessed during a 30 s Wingate cycle test. Plasma creatine kinase was measured from a fingertip blood sample. These variables were measured before, 1 h after and 1, 2, 3 and 7 days after 100 repetitions of the eccentric phase of the barbell squat exercise (10 sets x 10 reps at 80% concentric one-repetition maximum). Eccentric exercise resulted in elevations in creatine kinase activity above baseline (274+/-109 U x l(-1); mean +/- s(x)) after 1 h (506+/-116 U x l(-1), P < 0.05) and 1 day (808+/-117 U x l(-1), P < 0.05). Isometric strength was reduced (P < 0.05) for 7 days (35% at 1 h, 5% at day 7) and the rate of fatigue was lower (P < 0.05) for 3 days at 80 degrees and for 1 day at 40 degrees. Wingate peak power was reduced to a lesser extent (P < 0.05) than isometric strength at 1 h (13%) and, although the time course of recovery was equal, the two variables differed in their pattern of recovery. Eccentrically exercised muscle was characterized by an inability to generate high force and power, but an improved ability to maintain force and power. Such functional outcomes are consistent with the proposition that type II fibres are selectively recruited or damaged during eccentric exercise.     

预热适应对大鼠离心运动骨骼肌形态结构及HSP70表达的影响

目的:观察16天的预热适应对大鼠运动性骨骼肌损伤的影响;方法:成年大鼠80只,随机分为非预热适应组和预热适应组,各组又分为安静对照组、运动后即刻、运动后24h、运动后48h组和运动后6d组。预热适应模型:热刺激30～35min/天,共16天。末次热适应结束后,室温恢复24h,除安静对照组外,其余大鼠均进行一次离心运动至动物宰杀。取腓肠肌,进行光镜观察和HSP70表达测试;结果:1)预热适应运动大鼠骨骼肌损伤较单纯运动大鼠相应的时间点明显减轻;2)预热适应运动大鼠运动后即刻和运动后48hHSP70表达分别高于单纯运动后相对应时间点的值(P<0.05);结论:预热适应对大鼠运动性骨骼肌损伤有明显保护作用,其机理可能与长期(16天)的预热适应能上调HSP70蛋白表达有关。     

Effect of warm-up exercise on delayed-onset muscle soreness

Abstract

In this study, we wished to determine whether a warm-up exercise consisting of 100 submaximal concentric contractions would attenuate delayed-onset muscle soreness and decreases in muscle strength associated with eccentric exercise-induced muscle damage. Ten male students performed two bouts of an elbow flexor exercise consisting of 12 maximal eccentric contractions with a warm-up exercise for one arm (warm-up) and without warm-up for the other arm (control) in a randomized, counterbalanced order separated by 4 weeks. Muscle temperature of the biceps brachii prior to the exercise was compared between the arms, and muscle activity of the biceps brachii during the exercise was assessed by surface integral electromyogram (iEMG). Changes in visual analogue scale for muscle soreness and maximal voluntary isometric contraction strength (MVC) of the elbow flexors were assessed before, immediately after, and every 24 h for 5 days following exercise, and compared between the warm-up and control conditions by a two-way repeated-measures analysis of variance. The pre-exercise biceps brachii muscle temperature was significantly (P<0.01) higher for the warm-up (35.8±0.2°C) than the control condition (34.4±0.2°C), but no significant differences in iEMG and torque produced during exercise were evident between conditions. Changes in muscle soreness and MVC were not significantly different between conditions, although these variables showed significant (P<0.05) changes over time. It was concluded that the warm-up exercise was not effective in mitigating delayed-onset muscle soreness and loss of muscle strength following maximal eccentric exercise.     

Effects of cold water immersion on the symptoms of exercise-induced muscle damage.

Cryotherapy is an effective treatment for acute sports injury to soft tissue, although the effect of cryotherapy on exercise-induced muscle damage is unclear. The aim of this study was to assess the effects of cold water immersion on the symptoms of exercise-induced muscle damage following strenuous eccentric exercise. After performing a bout of damage-inducing eccentric exercise (eight sets of five maximal reciprocal contractions at 0.58 rad x s(-1)) of the elbow flexors on an isokinetic dynamometer, 15 females aged 22.0+/-2.0 years (mean +/- s) were allocated to a control group (no treatment, n = 7) or a cryotherapy group (n = 8). Subjects in the cryotherapy group immersed their exercised arm in cold water (15 degrees C) for 15 min immediately after eccentric exercise and then every 12 h for 15 min for a total of seven sessions. Muscle tenderness, plasma creatine kinase activity, relaxed elbow angle, isometric strength and swelling (upper arm circumference) were measured immediately before and for 3 days after eccentric exercise. Analysis of variance revealed significant (P < 0.05) main effects for time for all variables, with increases in muscle tenderness, creatine kinase activity and upper arm circumference, and decreases in isometric strength and relaxed elbow angle. There were significant interactions (P<0.05) of group x time for relaxed elbow angle and creatine kinase activity. Relaxed elbow angle was greater and creatine kinase activity lower for the cryotherapy group than the controls on days 2 and 3 following the eccentric exercise. We conclude that although cold water immersion may reduce muscle stiffness and the amount of post-exercise damage after strenuous eccentric activity, there appears to be no effect on the perception of tenderness and strength loss, which is characteristic after this form of activity.     

The effect of exercise-induced muscle damage on isometric and dynamic knee extensor strength and vertical jump performance

In this study, we assessed the effect of exercise-induced muscle damage on knee extensor muscle strength during isometric, concentric and eccentric actions at 1.57 rad · s -1 and vertical jump performance under conditions of squat jump, countermovement jump and drop jump. The eight participants (5 males, 3 females) were aged 29.5 - 7.1 years (mean - s ). These variables, together with plasma creatine kinase (CK), were measured before, 1 h after and 1, 2, 3, 4 and 7 days after a bout of muscle damaging exercise: 100 barbell squats (10 sets 2 10 repetitions at 70% body mass load). Strength was reduced for 4 days ( P ? 0.05) but no significant differences ( P > 0.05) were apparent in the magnitude or rate of recovery of strength between isometric, concentric and eccentric muscle actions. The overall decline in vertical jump performance was dependent on jump method: squat jump performance was affected to a greater extent than countermovement (91.6 - 1.1% vs 95.2 - 1.3% of pre-exercise values, P ? 0.05) and drop jump (95.2 - 1.4%, P ? 0.05) performance. Creatine kinase was elevated ( P ? 0.05) above baseline 1 h after exercise, peaked on day 1 and remained significantly elevated on days 2 and 3. Strength loss after exercise-induced muscle damage was independent of the muscle action being performed. However, the impairment of muscle function was attenuated when the stretch-shortening cycle was used in vertical jumping performance.     

The effects of topical Arnica on performance,pain and muscle damage after intense eccentric exercise

Abstract

The aim of the study was to determine if topical Arnica is effective in reducing pain, indicators of inflammation and muscle damage, and in turn improve performance in well-trained males experiencing delayed onset muscle soreness (DOMS). Twenty well-trained males matched by maximal oxygen uptake (V?O₂ Max) completed a double-blind, randomised placebo-controlled trial. Topical Arnica was applied to the skin superficial to the quadriceps and gastrocnemius muscles immediately after a downhill running protocol designed to induce DOMS. Topical Arnica was reapplied every 4 waking hours for the duration of the study. Performance measures (peak torque, countermovement and squat jump), pain assessments (visual analogue scale (VAS) and muscle tenderness) and blood analysis (interleukin-1 beta, interleukin-6, tumour necrosis factor-alpha, C-reactive protein, myoglobin and creatine kinase) were assessed at seven time points over five days (pre-, post-, 4, 24, 48, 72 and 96 hours after the downhill run). Participants in the topical Arnica group reported less pain as assessed through muscle tenderness and VAS 72 hours post-exercise. The application of topical Arnica did not affect any performance assessments or markers of muscle damage or inflammation. Topical Arnica used immediately after intense eccentric exercise and for the following 96 hours did not have an effect on performance or blood markers. It did however demonstrate the possibility of providing pain relief three days post-eccentric exercise.