人四肢骨骼肌两型肌纤维的横切面积研究

目的 为查清人四肢骨骼肌两型肌纤维的横切面积和直径。方法 用死后２４ｈ内男性尸体５具（年龄２１￣２８岁）,分别取双侧上、下肢２９块肌共４８块肌组织,作恒冷箱冰冻横切片。以肌球蛋白ＡＴＰ酶组织化学染色（ｐＨ９．４）,将肌纤维分为Ｉ型和Ⅱ型。用网形测微尺测量两型肌纤维的横切面积和直径。结果 人四肢不同骨骼肌的肌纤维粗细各不相同,其平均横切面积范围在１７８０￣４７６０μｍ＾２之间,平均直径为４７．６￣７     

酸性和碱性预孵育处理对骨骼肌肌纤维分型的影响—肌球蛋白ATP酶法

为比较分别经酸性和碱性预孵育液处理的肌球蛋白ATP酶反应法对骨骼肌肌纤维分型的影响．采用酸性（pH4．5）和碱性（pH10．4）预孵育肌球蛋白ATP酶法对大鼠躯干的腹外侧荐尾肌、后肢的处长伸肌相邻切片分别染色，然后比较相邻切片的相同肌纤维类型。结果显示两种预孵育液对ⅡA型肌纤维的分型设有影响，而酸性预孵育液处理后所鉴别的Ⅰ型和ⅡB型肌纤维，在经碱性预孵育液后有少数分别呈现为ⅡB型和ⅡA型肌纤维。本研究表明酸和碱性预孵育ATP酶染色对骨骼肌肌纤维的分型没有完全对应的“镇相”结果，这可能提示肌球蛋白ATP酶的活性在不同的酸性和碱性环境中有不同的稳定性。     

运动在骨骼肌肌纤维类型转变中的作用

骨骼肌纤维类型及其表达的专一蛋白同功型的多样性,是骨骼肌功能和适应性的结构和分子基础.肌球蛋白重链同功型被认为是决定肌纤维快、慢类型的主要因素,已成为区分肌纤维类型和研究肌适应性的分子标志.运动可以导致肌球蛋白重链不同亚型之间的转变.本文就肌球蛋白重链与骨骼肌纤维类型的关系,以及不同运动模式对骨骼肌纤维肌球蛋白重链同功型转变的影响作一综述.     

推拿干预2型糖尿病大鼠骨骼肌功能及肌纤维类型的转换

背景：既往研究表明,推拿可调控血糖的平衡,并能减缓骨骼肌的流失,促进肌纤维类型的转化,骨骼肌也是维持血糖平衡稳定的重要器官,但其具体关联和机制尚不明确。目的：探讨推拿对2型糖尿病大鼠骨骼肌结构和功能及骨骼肌纤维类型转换的影响。方法：取Wistar大鼠24只,通过高脂喂养联合小剂量链脲佐菌素腹腔注射建立2型糖尿病大鼠模型,将造模成功的18只大鼠采用随机数字表法分3组,每组6只：模型组不进行任何治疗,药物组灌胃给予盐酸二甲双胍,1次/d,6次/疗程,疗程间休息1 d,共灌胃治疗8个疗程;推拿组于丰隆、足三里、三阴交、血海等穴位用小动物按摩器进行推拿治疗,1次/d,6次/疗程,疗程间休息1 d,共治疗8个疗程。选择6只健康大鼠作为空白组,不进行任何干预。治疗结束后,检测大鼠血糖与血清胰岛素水平、肢体抓握力、游泳力竭时间、骨骼肌湿质量及腓肠肌中生肌决定因子、肌肉生长抑制素的蛋白及m RNA表达,采用ATPase染色观察骨骼肌纤维类型变化。结果与结论：(1)治疗结束后,与模型组比较,药物组、推拿组大鼠空腹血糖与血清胰岛素水平明显降低(P <0.01);(2)与模型组比较,推拿组大鼠肢体抓握...     

骨骼肌肌纤维生后发育及肌纤维类型的发育

骨骼肌是人体最大的运动器官,骨骼肌的研究一直为人们所关注.骨骼肌是由不同类型的肌纤维组成,且各种类型的肌纤维具有不同的收缩性质.生后发育过程中肌纤维型的构成对骨骼肌的发育是至关重要的.回顾文献,本文就骨骼肌生后发育,肌纤维分型进行综述.     

骨骼肌纤维内ATP酶的超微定位方法

骨骼肌纤维内ＡＴＰ酶的超微定位方法徐彦平何巍＊（中国医科大学第二电镜室，＊第一临床学院药剂科沈阳１１０００１）哺乳动物骨骼肌纤维的肌浆网膜上，存在着一种特殊的离子转运蛋白，其实质是一种Ｃａ２＋－Ｍｇ２＋依赖式ＡＴＰ酶，在Ｃａ２＋和Ｍｇ２＋存在的情况下...     

雄激素对大鼠骨骼肌纤维类型和超微结构的影响

本文应用光镜酶组化,电镜和RIAs技术,对给予外源性雄激素的大鼠骨骼肌纤维进行了定性和定量的研究观察。结果表明,服用雄激素可使骨骼肌纤维构成比发生转变,长期作用后,对骨骼肌各型纤维的超微结构有较大的不良现象。因此,我们认为运动员为提高运动成绩而服用雄激素的危害远远超过其可能的益处。     

AMPK/PGC-1α在有氧运动改善2型糖尿病大鼠骨骼肌萎缩中的作用

文题释义：腺苷酸活化蛋白激酶(AMPK)：是生物能量代谢调节的关键分子,AMPK在低氧、缺血、运动和营养缺乏等条件下易被激活,是研究糖尿病及其他代谢相关疾病的核心因子。 肌萎缩：宏观上表现为肌肉体积和质量的降低,微观上表现为肌纤维数目或直径减少。骨骼肌是摄取和利用葡萄糖的重要组织,肌萎缩的发生将增加2型糖尿病等代谢性疾病的发病风险。 背景：腺苷酸活化蛋白激酶(AMP-activated kinase,AMPK)对线粒体能量代谢功能的调节障碍是导致肥胖和2型糖尿病患者脂肪堆积的重要原因,长期慢性炎症反应还将进一步诱导骨骼肌萎缩的发生,有氧运动可以提高AMPK的活性并调节能量代谢,但是通过有氧运动提高AMPK改善2型糖尿病骨骼肌萎缩的作用机制尚不明确。 目的：探究有氧运动对2型糖尿病大鼠骨骼肌萎缩的影响,以及AMPK在其中的作用机制。 方法：采用高脂饲养联合链脲佐菌素注射建立2型糖尿病大鼠模型20只,建模后将大鼠分为糖尿病组(n=8)和糖尿病运动组(n=12),同时将正常大鼠15只分为安静对照组(n=6)和运动组(n=9),其中安静对照组和糖尿病组继续饲养4周,运动组和糖尿病运动组进行有4周有氧运动干预(跑速16 m/min,60 min/d,5 d/周),运动干预后取大鼠比目鱼肌免疫组织化学染色观察各组肌萎缩情况,Western blot检测AMPK、PGC-1α、MAFbx和MuRF1蛋白表达情况。实验已于2016-06-25通过北京体育大学运动科学实验伦理委员会批准(批准号：2016014)。 结果与结论：①高脂饲养联合链脲佐菌素注射建立的2型糖尿病模型大鼠血糖显著升高、体质量和胰岛素水平显著下降(P < 0.01);②糖尿病组大鼠比目鱼肌肌纤维平均横截面积较安静对照组显著降低(P < 0.01),糖尿病运动组大鼠比目鱼肌肌纤维平均横截面积较糖尿病组显著升高(P < 0.01);③糖尿病组大鼠比目鱼肌中AMPK和PGC-1α表达水平较安静对照组显著降低,MAFbx和MuRF1表达水平较安静对照组显著升高(P < 0.01);糖尿病运动组大鼠AMPK表达水平较糖尿病组显著升高,MAFbx和MuRF1的水平较糖尿病组显著降低(P < 0.01);④上述结果说明,有氧运动通过激活AMPK/PGC-1α信号通路,提高线粒体功能,抑制MAFbx和MuRF1表达水平,改善骨骼肌萎缩,在一定程度上恢复了2型糖尿病的代谢平衡。 ORCID: 0000-0003-0979-7741(王继) 中国组织工程研究杂志出版内容重点：组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程     

中药复方补剂对运动大鼠骨骼肌酶活性的影响

目的研究中药复方补剂对运动大鼠骨骼肌酶活性的影响。方法将40只SD大鼠分为补剂组和对照组,进行游泳运动后每组再分别分为即刻处死组和休息24h再行处死组,用酶组织化学方法染色观察骨骼肌中多种酶活性的变化。结果方剂组的运动鼠骨骼肌酶活性较对照组高（P〈0．05）。结论中药复方补剂能通过提高运动大鼠骨骼肌酶活性来改善骨骼肌细胞的能量供给,从而减缓大鼠体力性疲劳产生和促进大鼠体力性疲劳恢复。     

基于纤维增强超弹性基体模型的骨骼肌有限元模拟

为了进一步研究骨骼肌复杂的机械动力行为,采用有限元方法对骨骼肌行为进行力学分析.将骨骼肌视为肌纤维和超弹性基体构成的复合材料,纤维应力分为主动和被动两部分,主动应力依赖于疲劳状态、激励波形、收缩速度和现时长度,而被动应力与普通材料相同,仅依赖于现时应变.利用商用软件ABAQUS,对蛙大腿肌进行数值模拟,比较在周期激励作用下,不同时刻的单轴应变和代表性节点的位移分布规律.结果显示,骨骼肌表现出大变形特性,单轴最大应变达到69%.而且由于引入了疲劳函数,所采用的数值分析技术可模拟骨骼肌的主动与被动机械行为,且容易实现,结果稳定可靠.     

Denervation and Castration Effects on the Cross‐Sectional Area of Pubococcygeus Muscle Fibers in Male Rats

The number of fibers in skeletal muscles changes little through life; however, the cross‐sectional area of its fibers is modified as result of denervation and in some muscles by castration. The pubococcygeus muscle (Pcm) participates in micturition and ejaculatory processes and its fibers cross‐sectional area is reduced in castrated rats, but denervation effects remained unknown. Here, we used a model in which unilateral denervation of this muscle in gonadally intact and castrated male rats, allowed us to explore the neural and gonadal hormone effects on the cross‐sectional area of its fibers. Denervation significantly reduced the mean cross‐sectional area values; likewise, the percentage distribution of its fibers. We found that castration had a greater effect than denervation. Castration resulted in a lack of fibers from 2,000 to 3,999 μm², while in denervation it was from 2,500 to 3,999 μm². It was interpreted that the castration effect was due to a lack of the direct gonadal hormone effect on muscle fibers, and to a reduction of the indirect hormonal action in its neuromuscular complex. In denervated Pcm of gonadally intact animals these effects were present; however, in denervated but castrated animals these were absent. Thus, combined surgeries resulted in the lowest mean cross‐sectional area values with a restricted fiber distribution from 500 to 1,499 μm². In conclusion, the study in this important muscle showed that cross‐sectional area of its fibers depends on neural and direct/indirect gonadal hormone effects. Anat Rec, 296:1634–1639, 2013. © 2013 Wiley Periodicals, Inc.     

Hormonal Treatment Effects on the Cross‐sectional Area of Pubococcygeus Muscle Fibers After Denervation and Castration in Male Rats

We explore the interaction of muscle innervation and gonadal hormone action in the pubococcygeus muscle (Pcm) after castration and hormone replacement. Male Wistar rats were castrated and the Pcm was unilaterally denervated; after 2 or 6 weeks, the cross‐sectional area (CSA) of Pcm fibers was assessed. Additional groups of castrated rats were used to examine the effects of hormone replacement. At 2 weeks post surgeries, rats were implanted with Silastic capsules containing either dihydrotestosterone (DHT), estradiol benzoate (EB) or both hormones, and the CSA of Pcm fibers was assessed after 4 weeks of hormone treatment. At 2 weeks post surgeries, gonadectomy without hormone replacement resulted in reductions in the CSA of Pcm fibers, and denervation combined with castration increased the magnitude of this effect; further reductions in CSA were present at 6 weeks post surgeries, but again denervation combined with castration increased the magnitude of this effect. Hormone replacement with DHT resulted in hypertrophy in the CSA of nondenervated muscles compared to those of intact normal males, but this effect was attenuated in denervated muscles. Hormone replacement with EB treatment prevented further castration‐induced reductions in CSA of nondenervated muscles, but denervation prevented this effect. Similar to that seen with treatment with EB alone, combined treatment with both DHT and EB prevented further reductions in CSA of Pcm fibers in nondenervated muscles, but again denervation attenuated this effect. Thus, while hormone replacement can reverse or prevent further castration‐induced atrophy of Pcm fibers, these effects are dependent on muscle innervation. Anat Rec, 300:1327–1335, 2017. © 2017 Wiley Periodicals, Inc.     

Effect of Endurance Training on the Capacity of Red and White Skeletal Muscle of Mouse to Oxidize Carboxyl-14C-labelled Palmitate

Three groups of mice were trained for 1, 4 and 5 months according to different running programs on a motor driven treadmill and the fatty acid oxidation capacity (FAO) and the activities of some enzymes of energy metabolism (cytochrome c oxidase, malate dehydrogenase, triosephosphate dehydrogenase, and lactate dehydrogenase) were determined from m. quadriceps femoris (MQF). Endurance training increased the FAO [5-month training, 4 days/week, 30 min/day 22% (p<0.05); 1-month training, 7 days/week, 150 min/day 37% (p<0.001); 4-month training, 5 days/week, 60 min/day 24% (p<0.05)]. The activities of cytochrome c oxidase and malate dehydrogenase increased approx. 30% (p< 0.001) whereas triosephosphate dehydrogenase and lactate dehydrogenase activities were not prominently influenced by training. The predominantly red part of MQF of untrained animals oxidized palmitate four times faster than the predominantly white part. The activities of cytochrome c oxidase and malate dehydrogenase were two times higher showing pronounced FAO in the red part. Endurance training increased the FAO and activities of oxidative enzymes in the red and white parts and in the whole muscle relatively equally resulting in similar differences between the muscle types after training. The absolute increase in the FAO of the red muscle was, however, manyfold when compared in chemical units to the white muscle.     

Effects of Deafferentation on the Size and Myosin Phenotype of Muscle Fibers on Stretching of the Rat Soleus Muscle in Conditions of Gravitational Unloading

The aim of the present work was to assess the contributions of the reflex and local components to preventing decreases in the size and changes in the ratio of fibers containing the slow and fast isoforms of myosin heavy chains during chronic stretching of a postural muscle in rats in conditions of gravitational unloading. A unilateral surgical deafferentation method was used. The results demonstrated that deafferentation of the hindlimb had no effect on preventing reductions in muscle fiber size in conditions of chronic muscle stretching in conditions of gravitational unloading. The results obtained from these experiments did not support the hypothesis that the predominant contribution to preventing the development of atrophic changes comes from activation of muscle afferents in chronic stretching of the unloaded muscle. Deafferentation of both suspended animals and those with normal motor activity led to increases in the proportion of soleus muscle fibers containing the slow isoforms of myosin heavy chain.     

Ultrastructure of an Endometrial Stromal Nodule with Skeletal Muscle

The ultrastructural appearance of an endometrial stromal nodule with prominent smooth and skeletal muscle differentiation is described. This is the first reported case of endometrial stromal nodule with a heterologous skeletal muscle component and emphasizes the value of electron microscopy and its correlation with immunohistochemistry in the study of rare or complex lesions.     

用肌桥桥接周围神经缺损的远期观察

本文用大白鼠为实验模型,在用肌桥修复神经缺损近期形态学变化的基础上,进一步对术后6个月的肌桥作了观察。结果表明:肌桥中的肌纤维进一步退化、萎缩,为神经纤维所代替;再生神经纤维生长良好,部分有无完整髓鞘,呈成熟状态,组化染色已能恢复至正常;腓肠肌刺激有收缩反应,运动终板清晰可见。进一步提示:肌桥作为移植体用于修复周围神经缺损,远期疗效良好。     

Expression of E-Selectin in Ischemic and Reperfused Human Skeletal Muscle

This work was undertaken to assess the role of endothelial E-selectin in the development of neutrophil accumulation into the ischemic and reperfused human skeletal muscle and eventually in the genesis of ischemia-reperfusion syndrome. Twelve patients affected by abdominal aortic aneurysm who were undergoing reconstructive vascular surgery were studied. Muscle biopsies from the right femoral quadriceps were taken (1) immediately after anesthesia, as control samples, (2) before declamping the aorta, as ischemic samples, and (3) 30 minutes after reperfusion and then processed for immunohis-tochemical and ultrastructural analysis. Immunohistochemistry revealed a strong positive reaction for E-selectin on the venular endothelium during ischemia and reperfusion. Ultrastructural investigation showed that reactivity for E-selectin matched neutrophil accumulation of the skeletal muscle tissue. This phenomenon was dependent upon a complex series of events that included neutrophil adhesion to the inner surface of the postcapillary venules, passage through endothelial intercellular junctions, and migration distally into the interstitial spaces of the skeletal muscle tissue. Neutrophil tissue infiltration was also associated with ultrastructural signs of tissue damage at reperfusion. This is in agreement with accumulating evidence indicating a role for tissue infiltrating neutrophils in the genesis of toxic O₂ free radicals. Our data suggest that E-selectin expression on the vascular endothelium of human skeletal muscle May-June represent a key regulatory point in the process of neutrophil tissue accumulation and indicate an active role for the venular endothelium in the development of human ischemia-reperfusion syndrome.