针刺和静力牵张对大负荷运动后人骨骼肌Z带变化影响的免疫电镜研究

我们用兔抗人α-actinin(α-辅肌动蛋白)抗血清和羊抗兔IgG-胶体金复合物作为标记物,在由Lowicryl K4M包埋的组织超薄切片上定位Z带蛋白α-actinin。在大负荷斜蹲后48小时从6名男性受试者(年龄为22—22岁)的两侧腿股外肌中取得活检样品,并在运动后不同时刻及活检取样前对随机确定的每一受试者的一条腿进行针刺或静力牵张,另一侧腿作对照。结果发现,针刺或静力牵张腿Z带特异性标记密度比其对照腿高。此外,针刺或静力牵张还能使Z带发生超微结果的变化率分别减少36％和22％,并使显著变化的比例减少,轻度变化的比例增加。以上观察结果揭示了针刺或静力牵张能抑制由于α-actinin的解聚或降解引起的Z带超微结构变化过程,或者通过加速α-actinin的聚合或合成而促进Z带超微结构的恢复。     

全身振动训练对去卵巢大鼠骨骼肌的影响机制

摘要：目的：探讨全身振动训练对骨质疏松后骨骼肌的改善及肌肉生长抑制素（MSTN）的影响,为更好的缓解骨质疏松提供运动医学的科学依据。方法：3 月龄雌性 SD 大鼠随机分为假手术组（Sham 组）,去卵巢组（OVX 组）,全身振动训练组（OVX-V组）,每组10只。8 周去卵巢建模成功后,OVX-V组开始振动训练（7 d/周,2 次/d,15 min/次、间隔 10 min,振动频率50 Hz、振幅 0.9 mm）,其余2组正常饲养。8 周 后,测定子宫湿重、子宫内膜厚度;ELISA检测E2、P、T4的变化;RT-qPCR和western blot检测MSTN 、Act RIIB、Akt、m TOR、FoxO1的表达。结果：与OVX 组相比,全身振动训练后大鼠体重减轻、抓力增加;子宫湿重、子宫内膜厚度增加,但无统计学意义;激素水平E2和T4明显升高;并且振动训练显著下调Akt, mTOR,p-Akt 和p-mTOR的表达,显著上调MSTN,ActRIIB, FoxO1 和它的磷酸化表达。结论：8 w全身振动训练对骨质疏松大鼠骨骼肌质量有改善作用,其机制可能是通过促进蛋白合成抑制蛋白降解。MSTN有望作为一种新的肌肉力量评价指标,联合振动训练应用于运动训练和运动康复领域中。     

负荷运动对人体骨骼肌卫星细胞的影响

骨骼肌在运动损伤、发育和重建等过程中卫星细胞具有重要的生理作用。适宜的运动训练可以激活肌卫星细胞,使之增殖并向成肌的肌卫星细胞转化。文章阐述了骨骼肌卫星细胞的特征、负荷运动对肌卫星细胞的影响,以及运动对卫星细胞的激活与增殖的作用机制;并对人体衰老过程中肌卫星细胞的变化规律进行分析与探讨。     

MSTN调控的研究进展

肌肉生长抑制素(Myostatin,MSTN)对骨骼肌生长有负调控作用,调控MSTN对防治各种与骨骼肌衰退有关的疾病以及提高运动能力都有重要意义。通过检索中国期刊网全文数据库以及PubMed数据库相关文献,对MSTN调控研究进展进行综述。认为:MSTN的信号传导途径主要有3条;MSTN受多项因素的调控,除了基因敲除和变异外,较为显著的两项是力量训练和化学试剂调控;不同形式的力量训练均能抑制MSTN及其受体的表达,但效果有所差别;一些化学试剂如MSTN阻断剂、拮抗剂、抗体等在动物实验中都取得了明显的增肌效果,但MSTN抗体在人体实验中还未见成效。     

Effects of an 8-weeks erythropoietin treatment on mitochondrial and whole body fat oxidation capacity during exercise in healthy males

The present investigation was performed to elucidate if the non-erythropoietic ergogenic effect of a recombinant erythropoietin treatment results in an impact on skeletal muscle mitochondrial and whole body fatty acid oxidation capacity during exercise, myoglobin concentration and angiogenesis. Recombinant erythropoietin was administered by subcutaneous injections (5000 IU) in six healthy male volunteers (aged 21 ± 2 years; fat mass 18.5 ± 2.3%) over 8 weeks. The participants performed two graded cycle ergometer exercise tests before and after the intervention where VO_2max and maximal fat oxidation were measured. Biopsies of the vastus lateralis muscle were obtained before and after the intervention. Recombinant erythropoietin treatment increased mitochondrial O₂ flux during ADP stimulated state 3 respiration in the presence of complex I and II substrates (malate, glutamate, pyruvate, succinate) with additional electron input from β-oxidation (octanoylcarnitine) (from 60 ± 13 to 87 ± 24 pmol · s^?1 · mg^?1 P < 0.01). β-hydroxy-acyl-CoA-dehydrogenase activity was higher after treatment (P < 0.05), whereas citrate synthase activity also tended to increase (P = 0.06). Total myoglobin increased by 16.5% (P < 0.05). Capillaries per muscle area tended to increase (P = 0.07), whereas capillaries per fibre as well as the total expression of vascular endothelial growth factor remained unchanged. Whole body maximal fat oxidation was not increased after treatment. Eight weeks of recombinant erythropoietin treatment increases mitochondrial fatty acid oxidation capacity and myoglobin concentration without any effect on whole body maximal fat oxidation.     

下坡跑运动与重复运动对大鼠骨骼肌组织病理学影响研究

为探讨重复运动后大鼠骨骼肌损伤适应过程中组织病理改变,将大鼠分为正常对照组、下坡跑运动组、重复运动组并分别进行下坡跑运动及重复运动,观察下坡跑运动及一周后重复运动后即刻、24 h、48 h、72 h、168 h大鼠股四头肌病理切片的变化。结果表明：重复运动组各时间段形态学变化较一次大强度下坡跑运动组有所减轻,表现为下坡跑运动后24 h肌纤维不完全断裂,损伤处细胞溶解,48 h病灶开始逐步清除,至168 h后仍有部分病灶存在。重复运动后症状相应减轻,48h后病灶清除速度明显加快,168 h后基本恢复到正常水平。这可能是损伤修复后肌纤维再生重建、肌节长度趋于均等化、增强了抗损伤能力的结果,提示重复运动能有效加速骨骼肌损伤修复的速度,加速骨骼肌对运动训练刺激的适应性。     

层状材料HNbWO_6与Fe_2O_3的组装

利用剥离-组装法制备出复合材料HNb WO6/Fe2O3,以粉末X-射线衍射(XRD)、扫描电子显微镜(SEM)、拉曼光谱(Raman)等检测手段表征其微观结构和骨架特征。结果表明复合材料具有较规整的结构,而且主客体之间存在着相互作用。     

Melatonin therapy for blunt trauma and strenuous exercise: A mechanism involving cytokines,NFκB,Akt, MAFBX and MURF-1

Muscle injury occurs due to trauma, strenuous exercise or sports activities; most people affected are athletes. Ineffectively treated muscle injury can negatively affect sports careers and quality of life after retirement from sports. Reports have indicated that the current therapeutic management of muscle injury, particularly anti-inflammatory drugs, are not necessarily effective. Therefore, better therapies are required. Accumulating evidence has demonstrated melatonin’s potent antioxidant and anti-inflammatory actions against muscle pathology in sarcopenia or atrophy in systemic disease. However, the underlying mechanisms for the protective effect of melatonin in the context of trauma/strenuous exercise are multifactorial and not well described. This paper reviews data on melatonin’s impact on muscle injury and findings that points toward the mechanisms through which melatonin achieves muscle protection. The general concept described in this review is that melatonin inhibits NFκB, reduces cytokine expression, increases Akt that downregulates the ratio of MAF_BX and MURF-1 in order to limit the extent of muscle injury and promote muscle recovery post-injury. The work discussed in this review supports the notion that melatonin may be considered a possible therapy against trauma/sports related muscle injury. Inclusion of melatonin as a therapy in sports medicine could therefore provide a better treatment option for injured athletes and sports individuals.