大鼠胸深肌肌纤维型的组成及分布

目的探讨SD大鼠胸深肌的肌纤维型组成和分布,借以了解该肌功能。方法采用Guth-Samaha肌球蛋白ATP酶组织化学染色法并稍做改良,对成年SD大鼠胸深肌冰冻切片进行肌纤维分型研究。结果大鼠胸深肌经肌球蛋白ATP酶组织化学染色后可明确分出2型肌纤维,即明亮色白的Ⅰ型纤维(慢缩纤维)和幽暗深褐的Ⅱ型纤维(快缩纤维),并且,两种纤维在肌内呈棋盘样均匀分布;图像分析仪下计数Ⅱ型纤维达到65%±6%,而Ⅰ纤维仅占35%±5%,前者明显高于后者(P<0.01)。结论大鼠胸深肌以Ⅱ型纤维为主,属于力量和速度型肌。     

大鼠腹外斜肌肌纤维型组成及分布研究

目的探讨大鼠腹外斜肌的肌纤维型组成和分布,借以了解该肌功能,并为运动训练模型的建立提供理论依据和研究平台。方法采用Guth-Samaha肌球蛋白ATP酶组织化学染色法并稍做改良,对成年SD大鼠腹外斜肌冰冻切片进行肌纤维分型研究。结果SD大鼠腹外斜肌经肌球蛋白ATP酶组织化学染色后可明确分出2型肌纤维,即明亮色白的Ⅰ型纤维(慢缩纤维)和幽暗深褐的Ⅱ型纤维(快缩纤维),并且,2种纤维在肌内呈棋盘样均匀分布;图像分析仪下计数Ⅱ型纤维达到(84.8±5.3)%,而Ⅰ纤维仅占(15.2±2.1)%,前者占绝对优势(P<0.01)。结论SD大鼠腹外斜肌以Ⅱ型纤维为主,除了起保护腹腔脏器作用外,还参与力量和速度运动。     

手肌的肌纤维型分布

取５例（男４，女１）２１－３７岁死后１２ｈ内的人尸两侧手肌共１９０块，用肌球蛋白ＡＴＰ酶法，系统研究了手部各肌的肌纤维型分布。结果表明，人类手肌Ｉ型（慢缩）纤维的平均百分率４４％－６７％。从总体看，手肌中慢缩纤维（总平均为５５．８％）略占优势。其中外侧群Ｉ型纤维占６１．５％，中间群占５１．９％，内侧群占５７．６％。内、外侧群的慢缩纤维均高于中间群，并存在显著性差异（Ｐ＜０．０５，Ｐ＜０．０１）。在     

小圆肌和大圆肌的肌纤维型分布研究

目的：探讨小圆肌和大圆肌的肌纤维型分布特征和构成比例及其相关生理功能,为骨骼肌运动生理和临床应用提供形态学数据.方法：选取4例16～40岁（均死于非神经肌性疾病）死后12 h内的国人尸体两侧小圆肌和大圆肌,在肌腹中部取材共16块立即置入液氮,随后作恒冷箱冰冻横切片（-20℃,厚10 μm）,用肌球蛋白ATP酶法染色,研究两肌的肌纤维分型分布、测定各肌I型（慢缩）、Ⅱ型（快缩）肌纤维的构成比例.结果：（1）小圆肌和大圆肌的肌纤维分成Ⅰ型、Ⅱ型,两型肌纤维呈棋盘格式混杂分布;（2）两肌的Ⅰ型肌纤维平均百分率分别为57.9%和55.0%;（3）同型肌纤维的分布频率在左、右侧别之间比较差异无统计学意义（P＞0.05）.结论：小圆肌和大圆肌以I型肌纤维分布稍占优势,为国人肌纤维型提供基础资料.     

大鼠胸浅肌肌纤维型组成及其葡萄糖转运蛋白4表达特征

目的:研究大鼠胸浅肌不同肌纤维型的组成分布及其葡萄糖转运蛋白4(GLUT4)表达差异,了解该肌功能。方法:采用Guth-Samaha肌球蛋白ATP酶染色法并稍做改良,对成年SD大鼠胸浅肌冰冻切片进行肌纤维分型研究,并用免疫组织化学法对肌纤维分型后的切片进行GLUT4表达分析。结果:大鼠胸浅肌经肌球蛋白ATP酶染色后可明确分出明亮色白的Ⅰ型纤维和幽暗深褐的Ⅱ型纤维,2种纤维在肌内呈棋盘样均匀分布;Ⅰ型纤维比例为(52·6±6·3)%,Ⅱ纤维为(48·4±5·7)%,两者比例均等。免疫组织化学显色结果显示,GLUT4主要存在于包裹肌束的肌膜和Ⅰ型纤维膜上,而Ⅱ型纤维膜表达不明显。结论:大鼠胸浅肌两型纤维比例均等,属耐力兼速度型肌;Ⅰ型纤维膜的GLUT4表达高于Ⅱ型纤维,表明前者葡萄糖摄取能力高于后者。     

人的缝匠肌肌纤维型分布

本文研究人缝匠肌上、下半肌纤维型的分布,目的是比较上、下半肌纤维型的分布差异,探讨双关节肌的结构和功能关系。结果指出,缝匠肌上半Ⅰ型纤维占60.7±10.1%,下半Ⅰ型纤维占56.9±6.6%,统计学上无显著性差异。左、右侧比较也未见差异。作者认为缝匠肌的上、下半在功能上是一致的。     

斜方肌各亚部的肌构筑肌梭分布研究及其临床意义

目的 为斜方肌亚部的临床应用提供形态学基础。 方法 (1)用肌构筑法对10具成人尸体的斜方肌亚部进行肌构筑学研究。(2)用体视学方法对6具成人尸体的斜方肌亚部进行肌梭分布研究。 结果 (1)斜方肌降部的肌重(30.71±7.40 )g、肌长(10.45±1.62) cm、肌纤维长(9.18±0.99) cm、生理横切面积(3.11±0.72) cm2,水平部的肌重(44.14±10.61) g、肌长(8.65±0.84) cm、肌纤维长(7.14±0.84) cm、生理横切面积(5.89 ±1.66) cm2,升部的肌重(44.89±11.67) g、肌长(11.83±1.12) cm、肌纤维长(9.09±0.94) cm、生理横切面积(5.37±1.55) cm2。(2)斜方肌降部的肌梭密度(39.05±5.08)个/cm3,水平部的肌梭密度(24.48±6.50)个　/cm3,升部的肌梭密度(21.68±6.64)个/cm3。 结论 (1)根据斜方肌各亚部的构筑学特征,推测斜方肌降部和水平部在肩部运动中主要是保持和稳定肩胛骨位置,斜方肌的降部与升部在肩胛骨的旋转中起重要作用。(2)斜方肌降部的肌梭密度明显高于水平部和升部。     

人指屈肌和指胂肌的肌纤维型构成及年龄差异

用尸检取材，肌球蛋白ＡＴＰ酶染色法，检测了不同年龄组（共１８例，３－６９岁）指浅屈肌、指深屈肌和指伸肌的肌纤维型构成。结果表明：中青年组各肌的Ｉ型纤维比例分别为指浅屈肌４７．２％，指深屈肌４４．７％，指伸肌４７．７％，各肌之间无明显差异。     

Composition of Muscle Fiber Types in Rat Rotator Cuff Muscles

The rat is a suitable model to study human rotator cuff pathology owing to the similarities in morphological anatomy structure. However, few studies have reported the composition muscle fiber types of rotator cuff muscles in the rat. In this study, the myosin heavy chain (MyHC) isoforms were stained by immunofluorescence to show the muscle fiber types composition and distribution in rotator cuff muscles of the rat. It was found that rotator cuff muscles in the rat were of mixed fiber type composition. The majority of rotator cuff fibers labeled positively for MyHCII. Moreover, the rat rotator cuff muscles contained hybrid fibers. So, compared with human rotator cuff muscles composed partly of slow‐twitch fibers, the majority of fast‐twitch fibers in rat rotator cuff muscles should be considered when the rat model study focus on the pathological process of rotator cuff muscles after injury. Gaining greater insight into muscle fiber types in rotator cuff muscles of the rat may contribute to elucidate the mechanism of pathological change in rotator cuff muscles‐related diseases. Anat Rec, 299:1397–1401, 2016. © 2016 Wiley Periodicals, Inc.     

Muscle Spindle Composition and Distribution in Human Young Masseter and Biceps Brachii Muscles Reveal Early Growth and Maturation

Significant changes in extrafusal fiber type composition take place in the human masseter muscle from young age, 3–7 years, to adulthood, in parallel with jaw‐face skeleton growth, changes of dentitions and improvement of jaw functions. As motor and sensory control systems of muscles are interlinked, also the intrafusal fiber population, that is, muscle spindles, should undergo age‐related changes in fiber type appearance. To test this hypothesis, we examined muscle spindles in the young masseter muscle and compared the result with previous data on adult masseter spindles. Also muscle spindles in the young biceps brachii muscle were examined. The result showed that muscle spindle composition and distribution were alike in young and adult masseter. As for the adult masseter, young masseter contained exceptionally large muscle spindles, and with the highest spindle density and most complex spindles found in the deep masseter portion. Hence, contrary to our hypothesis, masseter spindles do not undergo major morphological changes between young age and adulthood. Also in the biceps, young spindles were alike adult spindles. Taken together, the results showed that human masseter and biceps muscle spindles are morphologically mature already at young age. We conclude that muscle spindles in the human young masseter and biceps precede the extrafusal fiber population in growth and maturation. This in turn suggests early reflex control and proprioceptive demands in learning and maturation of jaw motor skills. Similarly, well‐developed muscle spindles in young biceps reflect early need of reflex control in learning and performing arm motor behavior. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.     

斜方肌对重度 Lenke1 型侧凸脊柱影响的有限元分析

目的 建立考虑斜方肌的脊柱侧凸有限元模型,探究斜方肌对脊柱的力学特性影响。 方法 建立脊柱侧凸患者胸腰椎及骶骨的有限元模型,并进行模型有效性验证。 之后加入肩胛骨和斜方肌,模拟分析上躯干不同工况下斜方肌对 Lenke1 型侧凸脊柱各部分的影响。 结果 脊柱-肌肉模型侧屈活动度比脊柱模型小 0. 23% ,椎间盘轴向旋转平均降低 0. 078°;软组织应力在小关节上分布更均匀,软组织所受应力变化更平稳;6 种工况中 87. 5% 的腰椎小关节所受应力减小。 结论 斜方肌可以增强脊柱抵抗变形的能力,同时使应力在脊柱上更符合循序渐进的分布,腰椎受力更小使得人体可以承受更多的外载荷。 所建脊柱-肌肉模型更贴合实际,对于临床具有一定的参考价值。目的 建立考虑斜方肌的脊柱侧凸有限元模型,探究斜方肌对脊柱的力学特性影响。 方法 建立脊柱侧凸患者胸腰椎及骶骨的有限元模型,并进行模型有效性验证。 之后加入肩胛骨和斜方肌,模拟分析上躯干不同工况下斜方肌对 Lenke1 型侧凸脊柱各部分的影响。 结果 脊柱-肌肉模型侧屈活动度比脊柱模型小 0. 23% ,椎间盘轴向旋转平均降低 0. 078°;软组织应力在小关节上分布更均匀,软组织所受应力变化更平稳;6 种工况中 87. 5% 的腰椎小关节所受应力减小。 结论 斜方肌可以增强脊柱抵抗变形的能力,同时使应力在脊柱上更符合循序渐进的分布,腰椎受力更小使得人体可以承受更多的外载荷。 所建脊柱-肌肉模型更贴合实际,对于临床具有一定的参考价值。     

人斜方肌的亚部划分与形态学测量

目的为斜方肌亚部肌移植的临床应用提供形态学资料。方法成人尸体30具,用大体解剖法对斜方肌进行亚部划分,并对斜方肌各亚部进行形态学测量。结果(1)斜方肌降部起自上项线内1/3、枕外隆凸、项韧带,肌束向下止于锁骨外侧1/3段的后缘。斜方肌水平部起自从第7颈椎到第3胸椎的全部棘突和棘上韧带,肌束水平向外止于肩峰内侧缘和肩胛冈嵴的上唇。斜方肌升部起自从第4胸椎到第12胸椎的全部棘突和棘上韧带,肌束斜向外上方,止于肩胛冈内侧端的结节上。(2)斜方肌的肌长14.04±4.95cm,肌腹长10.79±3.45cm,肌厚0.92±0.49cm,表面积239.77±32.71cm2。结论(1)人斜方肌有互异的肌纤维走行和起止点,可分三个亚部:降部、水平部和升部。(2)人斜方肌各亚部或同一亚部内不同部位的肌长、肌腹长和肌厚均各不相同。     

Human Masseter Muscle Fibers From the Elderly Express Less Neonatal Myosin Than Those of Young Adults

In contrast to limb muscles where neonatal myosin (MyHC‐neo) is present only shortly after birth, adult masseter muscles contain a substantial portion of MyHC‐neo, which is coexpressed with mature MyHC isoforms. Changes in the numerical and area proportion of muscle fibers containing MyHC‐neo in masseter muscle with aging could be expected, based on previously reported findings that (i) developmental MyHC‐containing muscle fibers exhibit lower shortening velocities compared to fibers with exclusively fast MyHC isoforms and (ii) transformation toward faster phenotype occurs in elderly compared to young masseter muscle. In this study, we detected MyHC isoforms in the anterior superficial part of the human masseter muscle in a sufficiently large sample of young, middle‐aged, and elderly subjects to reveal age‐related changes in the coexpression of MyHC‐neo with adult MyHC isoforms. MyHC isoforms were visualized with immunoperoxidase method and the results were presented by (i) the area proportion of fibers containing particular MyHC isoforms and (ii) the numerical proportion of fiber types defined by MyHC‐1, ‐2a, ‐2x, and ‐neonatal isoform expression from a successive transverse sections. We found a lower numerical and area proportion of fibers expressing MyHC‐neo as well as a lower area proportion of fibers containing MyHC‐1 in elderly than in young subjects. We conclude that the diminished expression of MyHC‐neo with age could point to a lower regeneration capacity of masseter muscle in the elderly. Anat Rec, 2012. © 2012 Wiley Periodicals, Inc.     

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.     

High‐Intensity Resistance Training with Insufficient Recovery Time Between Bouts Induce Atrophy and Alterations in Myosin Heavy Chain Content in Rat Skeletal Muscle

The aim of this study was to test whether high‐intensity resistance training with insufficient recovery time between bouts, could result in a decrease of muscle fiber cross‐sectional area (CSA), alter fiber‐type frequencies and myosin heavy chain (MHC) isoform content in rat skeletal muscle. Wistar rats were divided into two groups: trained (Tr) and control (Co). Tr group were subjected to a high‐intensity resistance training program (5 days/week) for 12 weeks, involving jump bouts into water, carrying progressive overloads based on percentage body weight. At the end of experiment, animals were sacrificed, superficial white (SW) and deep red (DR) portions of the plantaris muscle were removed and submitted to mATPase histochemical reaction and SDS‐PAGE analysis. Throughout the experiment, both groups increased body weight, but Tr was lower than Co. There was a significant reduction in IIA and IID muscle fiber CSA in the DR portion of Tr compared to Co. Muscle fiber‐type frequencies showed a reduction in Types I and IIA in the DR portion and IID in the SW portion of Tr compared to Co; there was an increase in Types IIBD frequency in the DR portion. Change in muscle fiber‐type frequency was supported by a significant decrease in MHCI and MHCIIa isoforms accompanied by a significant increase in MHCIIb isoform content. MHCIId showed no significant differences between groups. These data show that high‐intensity resistance training with insufficient recovery time between bouts promoted muscle atrophy and a transition from slow‐to‐fast contractile activity in rat plantaris muscle. Anat Rec, 2011. © 2011 Wiley‐Liss, Inc.     

Immunohistochemical Study of Fiber Types in Human Extraocular Muscles

Fiber types in human extraocular muscle (h-EOM) were examined immunohistochemicaliy with antibodies against slow tonic (anti-ALD) and slow twitch (anti-SOL) myosins. Four types of muscle fiber in h EOM were distinguishable according to their reactivities with these antibodies. Groups 1 and 2 fibers reacted with both antibodies, group 1 fibers showing stronger reactivity than group 2 fibers with anti-ALD. Group 3 fibers reacted only with anti-SOL. Group 4 fibers did not react with either antibody. The latter were the most common, and were the main fibers in both the peripheral (outer orbital) and central zones of h EOM. The next most common were group 1 fibers, which were located mainly in the peripheral layer. Group 2 fibers were less common, but were the second most common type in the central layer. Group 3 fibers were only minor constituents. Multiple innervations were observed in some fibers of groups 1 and 2, and group 1 fibers were suggested to be slow tonic myofibers in h-EOM. These specific immunohistochemical and physiological features of h-EOM seem to be the basis of the low morbidity seen in the usual types of muscular dystrophy. Acta Pathol Jpn 40: 808-814, 1990.     

肌桥内肌纤维相对长度及截面积的差异对缺损神经再生的影响

目的 :探求较理想的肌桥。方法 :对取材于犬的不同部位的肌桥内肌纤维相对长度和截面积进行镜下观测及桥接缺损神经的实验观察。结果 :缝匠肌的肌条内肌纤维与肌条长轴平行并且多与肌条等长 ;指浅屈肌肌纤维走向与肌条长轴夹角较大而且不与肌条等长。不同肌条的肌纤维截面积有很大差异 ,其中肌纤维走向与肌条长轴夹角较大的肌纤维的截面积也较大。由相对长度较大的肌纤维为主要构成的肌桥缝接缺损神经的再生效果较好。结论 :肌桥内肌纤维的相对长度的差异对缺损神经再生有较大影响