在鸡慢肌神经支配下由快肌碎片形成的新生肌肉保持快肌的某些性质

本工作使用肌肉的切碎移植的方法来作快、慢肌肉的运动神经的交叉支配。将鸡右侧前背阔肌(慢)摘除而使其神经留在原位,再将左侧后背阔肌(快)取出切碎并放在右前肌的空位(第一组),在另一组动物是将右前肌摘出切碎后仍放回原位(第二组)。数月后用电刺激慢神经并用等长杠杆记录肌肉的收缩。第一组动物的新生肌肉的单收缩显然比第二组快些,而且在高频(250/s)刺激下表现抑制现象。第二组动物的新生肌肉不但收缩较慢,而且与前背阔肌一样不产生高频抑制。上述现象证明鸡的由快肌碎片形成的新生肌肉仍保持快肌的某些性质,而且在慢肌神经支配下仍能如此。本工作也进一步提供了维金斯基抑制与神经无关而与肌肉有关的证据。本文推测肌肉很可能是通过其卫星细胞而把某些性质传给新生肌肉的。     

鸡前、后背阔肌去神经后对辣根过氧化物酶(HRP)的胞纳作用

本文报道了用辣根过氧化物酶(HRP)作为大分子标记物,以组织化学和生物化学方法观察了鸡前后背阔肌在去神经后的胞纳现象。结果表明,在去神经后发生肥大的前背阔肌和去神经后发生萎缩的后背阔肌同样都出现胞纳的明显增加。组织化学所观察的结果表明,浸泡在含 HRP 的任氏液中的有完整神经支配的前、后背阔肌只有极少数的肌纤维摄取 HRP,而在去神经的前、后背阔肌中则有不少的肌纤维内部出现 HRP 染色反应。这种反应在有的纤维表现为弥散性染色,有的表现为浓的 HRP 反应颗粒。生物化学的结果显示,去神经后的前、后背阔肌中 HRP 的相对含量分别比有神经支配的对照肌肉明显地增多54%和87%,我们在鸡前背阔肌用组织化学和生物化学所得的实验结果与 Thesleff 等人提出的关于肌肉萎缩机制的假设显然不符。本工作证实了肌肉的胞纳作用的增加并不一定最终导致肌纤维的变性和萎缩。     

成年鸡的前,后背阔肌的卫星细胞体外培养下早期发育特征的比较

用酶处理的方法分离出成年鸡前背阔肌(慢肌)和后背阔肌(快肌)中的卫星细胞,在无神经因素影响下分别进行体外培养,每天用相差显微镜观察并比较二者的发育特征。在本实验中不仅观察到一些学者已描述过的卫星细胞的体外发育过程和特征,还发现了快、慢肌的卫星细胞之间在发育上存在的时程差异,即前背阔肌的卫星细胞发育为成肌细胞所需的时间以及成肌细胞融合为肌管所需的时间均比后背阔肌的卫星细胞约少24h。支持了鸟类肌肉的卫星细胞本身带有某种发育倾向的猜想,并把快、慢肌在离体的发育过程中可鉴别出差别的时间从肌管提前到卫星细胞时期。     

“红”、“白”肌的水和电解质在去神经后及在发育过程中的变化

我们曾测得蛙的不同肌肉的钙与镁浓度有所不同(于宗瀚,1962),这种差异可能是由于白肌(快肌)与红肌(慢肌)肌纤维內外间隙不同所造成。为此我们选取了莱亨鸡的前背阔肌(anterior latissimus dorsi,简称前肌)和后背阔肌(posterior Iatissimus dorsi,简称后肌)为材料(因为前肌主要是由红肌纤维组成,而后肌基本上由白肌纤维构成),研究了它     

鸡肌肉在肉毒桿菌毒素中毒后发生的“慢”纤维肥大和“快”纤维萎缩

肉毒杆菌毒素象去神经一样,在鸡的“慢”肌和“快”肌引起形成鮮明对比的营养性变化。在肉毒中毒后1—8周純“慢”肌前背阔肌无例外地发生肥大,而純“快”肌后背阔肌則出现通常的萎縮。混合肌肉缝匠肌中毒后,其中“慢”和“快”两种纤维,相应地出现肥大和萎縮两种相反的营养性反应。     

鸡前、后背阔肌的代谢特征及其在去神经后变化的比较研究

1.比较了鸡的前和后背阔肌(简称前肌和后肌)正常和去神经后的氧消耗率和脂肪、糖元、乳酸、磷化合物含量及其有关的酶活力的变化。2.正常前肌的氧消耗率和细胞色素氧化酶活力及脂肪含量和脂肪酶活力都比正常后肌高,特别是脂肪含量和脂肪酶活力在前肌比在后肌高3—4倍。正常后肌的乳酸、糖 元、无机磷、CP、ATP 含量皆高于前肌,后肌的 CP 和 ATP 含量比前肌的约高一倍,特别是糖元在后肌比在前肌高6—7倍。正常前肌和后肌的磷脂含量和腺三磷酶活力相近。这些特点指出前肌与一般红肌纤维相似,后肌与一般白肌纤维相似。3.去神经后前肌和后肌的氧消耗率、细胞色素氧化酶活力及糖元含量的变化方向相反,氧消耗率和细胞色素氧化酶在前肌降低(20—30%),在后肌升高(40—50%),而糖元在前肌升高(20—90%),在后肌降低(30—40%)。脂肪含量在前肌去神经后四星期时稍降低(17%),在后肌去神经四、八星期时则显著升高(40—90%);去神经后前肌的脂肪酶活力基本不变,而后肌在去神经一星期肌肉还没萎缩时脂肪酶活力即已显著升高,达至正常值的5倍,并维持此高水平至去神经后八星期。前肌在去神经后一、四星期时 CP 含量降低(20—30%),ATP 不变化;后肌在去神经后一星期肌肉尚未萎缩时CP 和 ATP 含量即显著降低(40—50%),至四、八星     

鸡前、后背闊肌去神經后营养性变化的对比

在比較純粹的“慢”肌——鸡的前背闊肌和与它成对的“快”肌——后背闊肌对去神經的反应时,发現二者間有显著的不同。去神經后,后背闊肌表現出通常的萎縮,而前背闊肌則非但不萎縮,反而会肥大。此外又証明了鸡頸二腹肌中两种纤維成分在去神經后出現萎縮和肥大两种相反的变化。看来“慢”肌的神經-肌肉間营养性关系和“快”肌的很不同,至少在鸡是如此。     

鸡前、后背闊肌去神經后的蛋白貭和核酸含量变化的比較研究

(一)前文描写鸡的前背闊肌(簡称前肌)和后背闊肌(簡称后肌)在去神經后分別表現的肥大和萎縮現象。本文研究此二肌肉去神經后1,4,8周时相应的蛋白貭和核酸含量的变化。 (二)正常鸡的前肌或后肌的左、右两側的蛋白貭,核酸含量是很相近的。但前肌的結締蛋白,RNA和DNA含量高于后肌,而肌浆蛋白浓度則低于后肌。 (三)前肌去神經后随着肥大的发生,从1星期起,总蛋白、肌浆蛋白和收縮蛋白总含量都显著增加,4星期时达高峯,但相对量变化很少;結締蛋白总含量增加不显著,其相对含量有时甚至降低。这些結果証实前肌去神經后的肥大确是真正的肥大。 (四)后肌去神經后随着萎縮的发生,总蛋白、肌浆蛋白和收縮蛋白总含量都显著降低,但相对含量基本不变;結締蛋白总含量不变,因而相对含量显著增加。 (五)前肌和后肌去神經后RNA和DNA含量都增加,但变化时程有所不同。在这两肌肉去神經后的RNA和蛋白貭含量变化之間,还看不出有規律的关系来。     

不同类型骨胳肌中的锌、铁、铜、锰浓度

早在1952年 Fischer 即观察到兔的不同肌肉中 Na、K、Mg、Cl 浓度不同。1956年 Eichelberger 等发现狗大腿与小腿肌肉的离子浓度不同。1962年于观察到蛙不同肌肉的 Ca、Mg 浓度不同。这些都还没有考虑到肌肉类型的问题。1963年 Sréter 和Woo 发表了大鼠红、白肌 Na 与 K 的工作。1964年于发表了莱亨鸡前、后背阔肌(分别代表红、白肌)四种主要生理活性离子及氯化物的简报。这些都是有意识地从不同类型肌肉的角度来考虑离子浓度的问题。     

正常和去神经肌肉核糖核酸的碱基比例

鸡的前和后背闊肌(“慢”和“快”肌)去神經后发生肥大和萎縮的相反变化。肌肉肥大和萎縮分別代表肌肉蛋白质增加和减少。前文已报导,上述两肌肉在去神經后虽然蛋白质含量一增一减,它們的核糖核酸(RNA)含量却都升高,在蛋白质含量变化与RNA含量变化之間看不出什么有規律的关系。本文进一步探討,这两块生理特性如此不同的肌肉所合的RNA有无质的区別,以及在去神經后是否发生质的变化,先从测定RNA的碱基比例入手。为了比較,亦測定了正常和去神經的兔肌肉的RNA的碱基比例。     

Histochemical heterogeneity of intrafusal muscle fibres in slow and fast skeletal muscles of the rat

Summary Intrafusal muscle fibres of the slow soleus (Sol) and fast vastus lateralis (VL) muscles of the rat were studied histochemically. Serial transverse sections were incubated for the localization of succinate dehydrogenase (SDH), alpha glycerophosphate dehydrogenase (GPD) and adenosine triphosphatase (ATPase). The latter was examined further after preincubation in acidic solution held at either low or room temperature (R_T). The bag₂ intrafusal fibres in both muscles displayed high regular and acid stable ATPase, but low SDH and GPD activities. Bag₁ intrafusal fibres showed low to moderate regular ATPase, a regional heterogeneity after R_T acid preincubation (low activity in juxtaequatorial and high in polar zones), moderate SDH, but low GPD reactions. In both muscles the chain fibres usually exhibited high ATPase for both regular and cold acid preincubated reactions, but usually low activity after R_T acid preincubation; they had high SDH but variable GPD activities. In Sol muscle, however, approximately 25% of spindles contained chain fibres that showed high acid-stable ATPase reaction after both cold and R_T acid preincubation. In contrast, chain fibres in some VL spindles had a characteristically low ATPase reaction even after cold acid preincubation. This study, therefore, has delineated the existence of an inherent heterogeneity among chain fibres (with respect to their histochemical reactions) in muscle spindles located within slow and fast muscles and also between those found within populations of either Sol or VL muscle spindles.     

Muscle fibre composition of the eye muscles of the carp (Cyprinus carpio L.) defined on the base of histochemical observations

A histochemical study has been carried out on the eye muscles of the carp. On the base of the ATP-ase and SDH activity and with regard to the localization and diameter of muscle fibres six types of muscle fibres situated in the defined zones can be distinguished. The type 1 and 2 fibres display a moderately high ATP-ase activity at pH 9.4 and rather low activity after alkaline and acid preincubation. Type 1 shows a high SDH activity in contrast to type 2 with a low SDH activity. The other four types of fibres have the high ATP-ase activity at pH 9.4. Type 3 contains fibres with a moderately high ATP-ase activity after alkaline preincubation with a rather low activity after acid preincubation and with a low SDH activity. The fibres of type 4 characterized by the high ATP-ase activity after alkaline and acid preincubation and by the high SDH activity. The fibres of type 5 display high ATP-ase activity after alkaline and acid preincubation and the low SDH activity. They are situated in the white and intermediate fibre zones. The fibres of type 6 are comparable to the fibres of type 5, however they differ diameter and localization, i.e. they are situated in small diameter fibre zone. Using the electron microscope four types of fibres (A, B, C, and D) are found. They vary in the localization of T system, the organization of Z-line and in M-line appearance. In the type B of muscle fibres two different localizations of T system have been discerned.     

Data on muscle fibre conversion and fibre splitting in man

A high proportion of the "intermediate" muscle fibres, which are semi-dark after both acidic and alkaline preincubation in ATP-ase staining, was found in the thigh with heart failure. Characteristic patterns of fibre splitting were found mostly in jumpers' muscles. Possibilities of fibre subgroup transformation and fibre hyperplasia due to training are discussed.     

Ultrastructural transformation of fast chicken muscle fibres induced by nerve cross-union

Summary The fast posterior latissimus dorsi (PLD) muscle of newly hatched chickens was transposed and cross-innervated by the slow-type nerve originally innervating the anterior latissimus dorsi (ALD) muscle. The innervation and the ultrastructure of the cross-innervated posterior latissimus dorsi (PLD-X) muscle was investigated from one week up to 18 months after the operation and compared with that of the control fast (PLD-C) and control slow (ALD-C) muscles. All nerve terminals in the PLD-X muscle were of the slow type. Yet the degree of ultrastructural transformation differed from fibre to fibre. Only about 30% of PLD-X fibres had transformed ultrastructure closely resembling the control slow fibres. In this group of maximally altered fibres, the myofibrils had large diameters, wide Z lines and indistinct M lines as the control slow fibres. The amount of mitochondria was increased to levels found in control slow fibres. The mean percentage of triads was also comparable to that of control slow fibres, being approximately by two thirds lower than in control fast fibres.The differences in the degree of ultrastructural transformation are presumably due to different plasticity of muscle cells at the time of cross-innervation. In the transposed PLD-X muscles large areas undergo degeneration and regeneration. It is suggested that an almost complete changeover of the fibre type is only brought about after cross-innervation of newly differentiating muscle cells, whereas partial alteration occurs after reinnervation of young myofibres.The skillful technical assistance of Dr. Z. Liková, Mrs. M. Sobotková, Ing. M. Doubek and Mr. H. Kunz is gratefully acknowledged.     

Differentiation of slow and fast muscles in chickens

1. The development of the characteristic histochemical appearance of the slow anterior latissimus dorsi (ALD) and fast posterior latissimus dorsi (PLD) was studied in chickens during embryonic development as well as during regeneration of minced muscle. 2. During embryonic development the activity of the oxidative enzyme succinic dehydrogenase (SDH) is higher in the slow ALD muscle already at 16 days of incubation. At this time the fast PLD has a higher activity of the glycolytic enzyme, phosphorylase. Although the histochemical appearance of the two types of muscle is already different at 16 days, their contractile speeds are still similar. No difference in myosin ATP-ase was found in the two muscles in young embryos but in 20-day old embryos the two muscles became distinctly different when stained for this enzyme. 3. When PLD muscles in hatched chickens redeveloped during regeneration in place of ALD the histochemical characteristics of the regenerated muscle resembled ALD, and when ALD regenerated in place of PLD it resembled PLD. 4. It is concluded that the histochemical characteristics of slow and fast muscles become determined during early development, even before any difference in contractile properties can be detected and that they are determined by the nerve.     

A histoenzymatic study of rat intrafusal muscle fibres.

The histochemical activities of myofibrillar adenosine triphosphatase (ATPase), succinic dehydrogenase (SDH) and alpha glycerophosphate dehydrogenase (alpha-GPD) were studied in intrafusal muscle fibres of rat fast and slow muscles. The ATPase reaction was carried out after the three standard acid preincubations. The cold K2-EDTA preincubated ATPase reaction product was similar to that seen following the regular or alkali-preincubated ATPase reaction, except that the intermediate bag fibres exhibited much higher activity after cold K2-EDTA preincubation. Following either acetic acid solution or cold and room temperature K2-EDTA-preincubation, followed by the ATPase reaction, chain fibres of the fast muscles vastus lateralis and extensor digitorum longus exhibited a very low amount of reaction product as compared with those of the slow soleus. Veronal acetate and K2-EDTA preincubations (and equally preincubation in acetic acid solution) resulted in acid stable ATPase activity along the entire length of the typical bag fibres but only in the polar regions of the intermediate bag fibres. On the basis of differing alpha-GPD reaction, two sub populations of nuclear chain fibres were discovered in one spindle. It is a matter of conjecture, to what extent the histochemical differences of intrafusal fibres from fast and slow muscles reflects functional distinctions in the response to stretch of muscle spindles from fast and slow muscles.     

Differentiation of original and regenerated skeletal muscle fibres in mdx dystrophic muscles

The differentiation of both original muscle fibres and the regenerated muscle fibres following necrosis in mdx muscles was investigated using immunoblotting and immunocytochemical procedures. Before the onset of necrosis, postnatal skeletal muscles in mdx mouse differentiated well with only a slight delay in differentiation indicated by the level of developmental isoforms of troponin T. Prior to the onset of apparent myopathic change, both fast and slow skeletal muscle fibre types in mdx leg muscles also differentiated well when investigated by analysis of specific myosin heavy chain expression pattern. While the original muscle fibres in mdx leg muscles developed well, the differentiation of regenerated myotubes into both slow and distinct fast muscle fibre types, however, was markedly delayed or inhibited as indicated by several clusters of homogeneously staining fibres even at 14 weeks of age. The number of slow myosin heavy chain-positive myotubes amongst the regenerated muscle clusters was quite small even in soleus. This study thus established that while muscle fibres initially develop normally with only a slight delay in the differentiation process, the differentiation of regenerated myotubes in mdx muscles is markedly compromised and consequently delayed.     

Intrafusal fibre types in rat limb muscle spindles

Summary Morphological, histochemical and ultrastructural characteristics of intrafusal fibre types were studied in rat muscle spindles. The existence of three intrafusal fibre types, namely the typical bag, the intermediate bag and the chain fibres was confirmed. Intrafusal fibres differ in diameter, length and number of nuclei in the equatorial zone. Histochemically, typical bag fibres exhibit both alkali-and acid-stable ATPase activity and low SDH activity. Intermediate bag fibres possess low alkali-stable ATPase activity; after acid-preincubation, however, they have low activity only in the juxtaequatorial region, whereas in the polar zones they exhibit high acid-stable ATPase activity. The SDH activity varies from moderate to high. The chain fibres exhibit high alkali-stable and low acid-stable ATPase and high SDH activity in the extensor digitorum longus muscle, whereas in the soleus muscle the acid-stable ATPase activity varies from a low one to a high one, either among individual chain fibres in one spindle, and/or repeatedly along the fibre length.Since there are regional differences in morphological characteristics and in staining properties of intrafusal fibres, a reliable identification of intrafusal fibre types can only be achieved by an analysis of serial sections.     

Intrafusal fibre types in rat limb muscle spindles: morphological and histochemical characteristics.

Morphological, histochemical and ultrastructural characteristics of intrafusal fibre types were studied in rat muscle spindles. The existence of three intrafusal fibre types, namely the typical bag, the intermediate bag and the chain fibres was confirmed. Intrafusal fibres differ in diameter, length and number of nuclei in the equatorial zone. Histochemically, typical bag fibres exhibit both alkali- and acid-stable ATPase activity and low SDH activity. Intermediate bag fibres possess low alkali-stable ATPase activity; after acid-preincubation, however, they have low activity only in the juxtaequatorial region, whereas in the polar zones they exhibit high acid-stable ATPase activity. The SDH activity varies from moderate to high. The chain fibres exhibit high alkali-stable and low acid-stable ATPase and high SDH activity in the extensor digitorum longus muscle, whereas in the soleus muscle the acid-stable ATPase activity varies from a low one to a high one, either among individual chain fibres in one spindle, and/or repeatedly along the fibre length. Since there are regional differences in morphological characteristics and in staining properties of intrafusal fibres, a reliable identification of intrafusal fibre types can only be achieved by an analysis of serial sections.     

No classical type IIB fibres in dog skeletal muscle

Summary To analyse the fibre type composition of adult dog skeletal muscle, enzyme histochemistry, immunohistochemistry for type I, IIA and IIB myosins, and peptide mapping of myosin heavy chains isolated from typed single fibres were combined. Subdivision of type II fibres into two main classes according to the activity of the m-ATPase after acidic and alkaline preincubation proved to be rather difficult and was only consistently achieved after a very careful adjustment of the systems used. One of these sub-classes of type II fibres stained more strongly for m-ATPase activity after acidic and alkaline preincubation, was oxidative-glycolytic and showed a strong reaction with an anti-type IIA myosin. The other one, however, although unreactive with anti-IIA myosin, was also oxidative-glycolytic, and only showed a faint reaction with an anti-type IIB myosin. Peptide mapping of the myosin heavy chains of typed single fibres revealed two populations of heavy chains among the type II fibre group. Thus, in dog muscle, we are confronted with the presence of two main classes of type II fibres, both oxidative-glycolytic, but differing in the structure of their myosin heavy chains. In contrast to some reports in the literature, no classical type IIB fibres could be detected.