休克血浆对离体豚鼠心室乳头肌的电生理效应

目的:进一步阐明休克血浆对心肌细胞的影响.方法:本实验利用常规的玻璃微电极细胞内记录技术,观察了休克血浆对豚鼠心室乳头肌动作电位的作用.结果:用含一定浓度的正常血浆灌流时,豚鼠心室乳头肌细胞动作电位的各指标均无显著变化,而用等量的休克血浆灌流,动作电位的APA、OS均显著升高(P＜0.05),APD50、APD90、APD也明显延长(P＜0.05).结论:休克血浆可显著影响豚鼠心室乳头肌动作电位APA、OS的高度及动作电位的时程,可能与心肌缺血再灌注心律失常的发生有关.     

去甲肾上腺素对豚鼠乳头肌动作电位的影响

目的:研究去甲肾上腺素(NE)对豚鼠心室乳头肌动作电位的影响.方法:采用玻璃微电极细胞内引导技术,记录离体豚鼠心室乳头肌动作电位,在此基础上,观察NE对豚鼠心室乳头肌动作电位的影响及酚妥拉明的拮抗作用.结果:100μmol/L NE可使乳头肌动作电位时程(APD)明显延长(P<0.05),动作电位复极50%和90%时间(APD50 and APD90)明显延长(P<0.05).而100μmol/L酚妥拉明可使延长的APD、APD50、APD90明显恢复.结论:去甲肾上腺素可明显延长豚鼠心室乳头肌动作电位时程,而酚妥拉明可阻断此效应.     

中药薰洗对短跑运动员运动能力的影响

目的:研究中药薰洗对运动机体肌力的影响。方法:将具有行气活血、法风湿散寒作用的中药近10味,运用理代技术制成见效快、使用方便安全的中药外用薰洗液供运动受训练后使用将40例短跑运动员随机分为对照组和用药组,分别测定安静及运动后的肌力。结果:用药组肌力改善明显优于对照组。结论:以具有祛风湿散寒、行气活血作用的中药制成的中药薰洗剂,能有效改善运动机体运动后肌力,加快肌肉力量的恢复。具有明显地消除运动性肌肉疲劳的作用。     

Hip adductor muscle function in forward skating

Adductor strain injuries are prevalent in ice hockey. It has long been speculated that adductor muscular strains may be caused by repeated eccentric contractions which decelerate the leg during a stride. The purpose of this study was to investigate the relationship of skating speed with muscle activity and lower limb kinematics, with a particular focus on the role of the hip adductors. Seven collegiate ice hockey players consented to participate. Surface electromyography (EMG) and kinematics of the lower extremities were measured at three skating velocities 3.33 m/s (slow), 5.00 m/s (medium) and 6.66 m/s (fast). The adductor magnus muscle exhibited disproportionately larger increases in peak muscle activation and significantly prolonged activation with increased speed. Stride rate and stride length also increased significantly with skating velocity, in contrast, hip, knee and ankle total ranges of motion did not. To accommodate for the increased stride rate with higher skating speeds, the rate of hip abduction increased significantly in concert with activations of adductor magnus indicating a substantial eccentric contraction. In conclusion, these findings highlight the functional importance of the adductor muscle group and hip abduction–adduction in skating performance as well as indirectly support the notion that groin strain injury potential increases with skating speed.     

Evaluation of Criteria Associated with Abdominal Fitness Testing

Abstract

The continued use of the timed sit-up as a measure of abdominal fitness has been challenged. This study complements earlier work by evaluating a new modified curl-up test (CUT) against a standardized modified sit-up test (SUT). Results show that there is almost 60% unexplained variance between SUT and CUT scores for young, active adults. The lack of association between SUT and CUT is attributed to predetermined differences in dynamic abdominal and hip flexor muscle activity and active range of motion differences in trunk flexion between each test. In addition, angular displacement of the trunk is greater for women than men in CUT. Evidence from this study provides further support for the use of CUT as an alternative to SUT in abdominal fitness testing.     

吸气肌训练对常氧和低氧条件下运动呼吸功能的影响

目的:检测吸气肌训练(IMT)对常氧和低氧条件下运动效果的影响;方法:15名受试者用呼吸肌训练仪进行为期4周的训练,其中,对照组8人,采用15%PImax(最大吸气口腔压力);训练组7人,采用50%PImax。训练前后,在低氧和常氧条件下分别进行85%V.O2max的跑台力竭测试及功能测试;结果:IMT组PImax增加24.5%±3.1%。所有条件下力竭时间均未见改变。IMT组在常氧和低氧运动后呼吸肌疲劳均减少10%(P<0.05);在低氧条件下运动,V.O2减少8%～12%(P<0.05),心输出量减少14%±2%,通气量减少25%±3%;动脉血氧饱和度和肺扩散能力分别增加了4%±1%和22%±3%;结论:IMT可以明显改善低氧条件下运动的呼吸功能。     

力竭运动对小鼠骨骼肌6种元素含量的影响

利用高频电感耦合等离子体原子发射光谱法(ICP-PES)测定了小鼠一次性力竭游泳运动后，骨骼肌内铁(Fe)、锌(Zn)、铜(Cu)、硒(Se)、钙(Ca)、镁(Mg)6种元素含量的变化。结果表明，力竭运动后可使小鼠骨骼肌内Ca、Se含量明显上升，Cu元素含量基本不变，Fe、Zn、Mg含量则明显下降。     

训练前后补脾、补肾对大鼠脑、肾和骨肌组织SOD活性及MDA含量的影响

为了探讨运动前后补脾、补肾及其组合应用对脑、肾和骨骼肌自由基代谢的影响,将48只SD大鼠随机分为(A)安静对照组、(B)训练对照组、(C)训练补脾组、(D)训练补肾组、(E)训练前补脾后补肾组、(F)训练前补肾后补脾组,经7周递增负荷跑台训练,检测定量负荷后脑、肾和股四头肌组织的丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性及SOD/MDA值.结果表明:与B组相比,脑组织E、F组MDA含量低(P<0.01),F组的SOD/MDA值高(P<0.01);肾组织E组SOD活性和SOD/MDA值均高(P<0.01);股四头肌C组的MDA含量低(P<0.05).结论:训练前后补脾、补肾提高脑、肾、骨骼肌组织抗氧化功能,不同应用方式在不同组织效果和作用具有差异.     

川芎嗪对大鼠心肌细胞膜钙通道的影响及其作用机制

目的:观察川芎嗪(L ig)对心肌细胞膜钙通道及胞内游离C a2 浓度([C a2 ]i的影响,并探讨其作用机制。方法:急性分离大鼠心肌细胞,用特异性C a2 荧光探针F luo-3/AM负载细胞,激光共聚焦显微镜(LSCM)检测L ig作用后心肌细胞内[C a2 ]i的变化。结果:L ig(30μm o l/L)可降低细胞内[C a2 ]i;L-型钙通道阻断剂V erapam il(40μm o l/L)、1β受体特异阻断剂A teno lo l(900μm o l/L)和1α受体特异阻断剂Phen to lam ine(1×1-0 5m o l/L)预处理,均可不同程度地阻断L ig(30μm o l/L)对心肌细胞钙的作用;L ig(30μm o l/L)对1α受体特异激动剂Pheny lephrine(1×1-0 4m o l/L)、钙通道激动剂A 23187(900μm o l/L)和1β受体特异激动剂D obu tam ine(1×10-5m o l/L)引起的细胞内钙升高有抑制作用。不与血管紧张素Ⅱ的Ⅰ型受体(AT1R)阻断剂V a lsartan位点作用。结论:L ig对心肌细胞内[C a2 ]i的降低作用,是由细胞膜上的L-型钙离子通道、1α受体和1β受体介导的。     

运动与骨骼肌细胞凋亡

运动能力的下降与骨骼肌中的细胞凋亡有着密切的联系,细胞凋亡异常也与多种肌细胞疾病的发生机制有关。因此,研究运动训练与细胞凋亡的关系及运动导致骨骼肌细胞凋亡的机制意义重大。综述研究认为,运动可以诱导骨骼肌细胞凋亡,细胞凋亡发生的比率和程度与运动形式、运动强度和运动持续时间密切有关。这些问题的研究对于预防和处理运动导致的骨骼肌损伤以及如何开展行之有效的体育锻炼提供了理论指导。