中国对虾PENAEUS CHINENSIS（O′SBECK）肌肉系统的研究…

中国对虾肌肉含有快肌Ｉ、快肌Ⅱ和慢肌等三类型肌纤维，其主要区别之处有：肌节长度、粗／细肌丝排列与比率、线粒体和二联体含量多寡以及ＡＴＰ酶活性等特征，文中已作详细描述。     

牵拉增加肌梭传入放电的实验观察

目的观察牵拉刺激(刺激强度)及其它实验因素对肌梭放电频率的影响。方法制备蟾蜍离体坐骨神经-缝匠肌标本,用BL-420生物机能系统记录牵拉刺激及实验因素对肌梭传入放电活动的影响。结果牵拉刺激增强,肌梭的传入放电频率增加;牵拉力度相同时,快速牵拉较缓慢牵拉引发更多的肌梭放电。结论肌梭是肌肉长度感受器,有快适应和慢适应两种现象,其敏感性受肌肉长度及温度的影响。     

螯虾腹屈肌快,慢肌肌原纤维的蛋白质差异

测定螯虾腹屈肌的快、慢肌肌原纤维的蛋白质组成，结果表明，快、慢肌的副肌球蛋白、肌球蛋白轻链和肌鲈蛋白有较大差异。结果提示甲壳动物快、慢肌原纤维蛋白质的差异是造成、慢肌形态与功能差异的原因之一。     

手术治疗女阴癌24例随访观察

目的：对女阴癌手术适应症和手术方法的选择进行探讨。方法：根据临床资料和随访的结果进行分析。结果：手术未满5a复发扩散死亡2例，满5a生存18例，5a生存率为75％。腹股沟淋巴清扫保留大隐静脉和不作缝匠肌移植手术组并发症少。结论：早查、早诊、早治是保证手术疗效的关锋；手术方法的选择根据病变位置、范围大小和淋巴结转移情况而定，腹股沟淋巴清扫以保留大隐静脉和不作缝匠肌移植为宜。     

顽拗性种子黄皮胚轴细胞膜ATP酶活性电镜分析

选用顽拗性种子黄皮为实验材料,运用ＡＴＰ酶电镜组织化学方法,对种子胚轴细胞在贮存、脱水和萌动过程中ＡＴＰ酶活性进行了分析。发现与正常性种子不同,黄皮种子在贮存中就有较高的ＡＴＰ酶活性,种子脱水造成细胞原生质收缩是是细胞膜破裂和脱水伤害的主要原因。     

低聚糖和多肽联合补充对大鼠糖原代谢的影响

研究了联合补充低聚糖和多肽对中等强度长时间运动后大鼠肌糖原及肝糖原代谢的影响.结果表明:运动前补充低聚糖和多肽能显著节约体内肌糖原的使用;运动后慢肌糖原合成过程中存在先快后慢的恢复规律;运动前及运动后即刻结合补充低聚糖和多肽能显著促进运动后肝糖原的恢复;在运动后慢肌糖原恢复过程中,肝糖原先于肌糖原恢复.     

天花粉蛋白与腺嘌呤、单磷酸腺苷、三磷酸腺苷之间的相互作用

利用荧光光谱和透析平衡法研究了腺嘌呤、单磷酸腺苷（ＡＭＰ）、三磷酸腺苷（ＡＴＰ）与天花粉蛋白之间的相互作用。荧光光谱揭示腺嘌呤与天花粉蛋白结合后对其荧光强度影响较小，但使蛋白的荧光峰位红移，而ＡＭＰ和ＡＴＰ只引起蛋白荧光强度下降而不改变峰位。ＡＭＰ，ＡＴＰ引起的荧光强度下降包含着快慢两个过程。透析平衡法测得ＡＭＰ，ＡＴＰ与天花粉蛋白相互作用的结合常数分别为１．２×１０￣（－１）ｍｏｌ／Ｌ和４．５×１０￣（－５）ｍｏｌ／Ｌ，二者自由能之差为－２．２６ｋＪ／ｍｏｌ。     

亚种间杂交稻发育籽粒中ATP酶活性及其调节

以籼／粳亚种间杂交稻组合及其亲本为材料,研究了灌浆期籽粒中ＡＴＰ酶活性变化动态及其激素与多胺调控。结果表明：花后３￣１８ｄ籽粒中的ＡＴＰ酶活性,强势粒明显高于弱势粒,物质运转率或籽粒充实好的组合（亲本）高于物质运转率或籽粒充实差的组合（亲本）,灌浆初期籽粒中的ＡＴＰ酶活性与谷粒充实率、受精籽粒粒重和物质运转率呈极显著正相关;开花后２ｄ分别喷施低浓度ＡＢＡ（０．０５ｍｍｏｌ·Ｌ＾－１）、ＩＡＡ（０．     

肌动蛋白和肌球蛋白在共同性斜视眼外肌的表达研究

目的：研究共同性斜视患者眼外肌与正常人眼外肌的结构差异，探讨共同性斜视的可能发病机制。方法：收集共同性斜视患者弱侧眼外肌进行肌动蛋白和肌球蛋白免疫组织化学染色研究。结果：共同性斜视组慢肌纤维和快肌纤维数目明显减少，但未见肌纤维类型优势分布和肌纤维群组化现象；比较两组间慢肌纤维和快肌纤维数目比值差异无统计学意义（P〉0.05）：肌动蛋白和肌球蛋白的表达明显下降，与对照组相比，差异有显著性意义（P〈0．01）。结论：共同性斜视弱侧眼外肌发生肌源性的病理学改变：眼外肌纤维减少和收缩蛋白表达减弱在共同性斜视的发病中可能起重要作用：眼外肌快肌纤维和慢肌纤维的数目比例失衡可能不是共同性斜视产生眼位偏斜的原因。     

石刁柏非胚性细胞和胚性细胞的超微结构及ATP酶的定位

对石刁柏非胚性细胞及胚性细胞的超微结构及ＡＴＰ酶定位进行了观察，非胚性细胞内液泡大，大量的自体吞噬泡出现，在液泡膜上有ＡＴＰ酶的活性反应．胚性细胞的细胞核大，核移中，线粒体，质体，核糖体，高尔基体，内质网等细胞器增多，淀粉、脂滴积累，有较活跃的自体吞噬现象．细胞壁开始增厚，在细胞核，液泡膜，线粒体，内质网等部位有较高的ＡＴＰ酶活性，在部分细胞壁中也存在有ＡＴＰ酶活性反应沉淀     

Stimulation of Acanthamoeba actomyosin ATPase activity by myosin-II polymerization

Phosphorylation of the regulatory light chains of vertebrate smooth muscle or cytoplasmic myosins alters the structure of myosin monomers, favours myosin filament formation and stimulates the actin-activated Mg2+-ATPase of myosin. Similarly, in Dictyostelium and Acanthamoeba phosphorylation of the myosin heavy chains exhibits both polymerization and actin-activated Mg2+ATPase. Unfortunately, the relationships between phosphorylation, myosin assembly and activation of ATP hydrolysis are not fully understood in any of these systems, as there has been no way of varying the extent of polymerization of intact myosin without changing solution conditions or the level of myosin phosphorylation, parameters that may have independent effects on ATPase activity. Taking an entirely new approach, we have used monoclonal antibodies against the tail of Acanthamoeba myosin-II that cause filament disassembly to show that myosin polymerization itself stimulates actomyosin ATPase activity. With a fixed level of myosin-II phosphorylation and constant solution conditions, depolymerization of myosin-II filaments by antibodies causes a concomitant loss of actin-activated ATPase activity.     

Myosin isoenzyme redistribution in chronic heart overload.

Since the first observation by Spann et al., it has become clear that in cardiac hypertrophy induced by a mechanical overloading, the velocity of shortening of the cardiac muscle (Vmax) is reduced (see ref. 2 for review). Most authors agree that this mechanical alteration is accompanied by a decrease in the Ca2+-dependent ATPase activity of myosin (see ref. 3 for review). The molecular basis of such changes was unknown because the structural modifications of the myosin molecule were ill-defined. Nevertheless, it has recently been shown that, like skeletal muscle myosin, cardiac myosin is composed of several polymorphic forms, comparable to isoenzymes. In the skeletal muscle, new functional requirements can induce changes in both contractile activity and type of myosin isoenzyme synthesised. We now report that an increase in cardiac work produced by mechanical overloading in rats induces the preferential synthesis of a cardiac myosin isoenzyme characterised by specific immunological and electrophoretic properties and exhibiting a lower ATPase activity. This adaptive change could account for the reduced shortening speed of this hypertrophied cardiac muscle.     

Calcium regulation of molluscan myosin ATPase in the absence of actin

In the myosin-linked regulatory mechanism typified by the molluscan scallop adductor muscle, contraction is controlled by Ca2+ binding to sites on the thick filament protein, myosin. The regulatory light chains of myosin heads are involved directly in this mechanism and early studies suggested that, in the absence of Ca2+, these subunits prevent the interaction of a myosin-adenosine nucleotide complex with the actin-containing thin filament. Subsequently, Ashiba et al. reported that the steady-state ATPase of molluscan myosin exhibits a limited degree of Ca2+ activation in the absence of actin. Recently, however, we have shown that steady-state ATPase activity in relaxing conditions is dominated by the unregulated molecules in the myosin preparation. Single-turnover kinetic methods are required to monitor the highly suppressed ATPase activity of the regulated population. Using the latter approach, we report here that scallop myosin ATPase is reduced about 100-fold on removal of Ca2+. The regulatory light chains maintain the relaxed state via conformational changes which suppress the product release steps, irrespective of the presence of actin.     

Purification and characterization of myosin from wheat mitochondria

Myosin was purified from wheat mitochondria using DE-52 anion exchange chromatography and Sephacryl S-300 gel filtration. The molecular weight of its heavy chain is about 210 ku, similar to that of muscle myosin Ⅱ(205 ku), and it could be recognized by the polyclonal antibodies against human skeletal muscle myosin Ⅱ. The ATPase activity of the mitochondrial myosin stimulated by F-actin from chicken muscle is 202.5 nmoles Pi/min·mg. The mitochondrial myosin could be activated by Ca²⁺ and was not inhibited by Ca²⁺ at high concentration. The results demonstrate that the myosin of wheat mitochondria shares some similarities with the skeletal muscle myosin Ⅱ.     

Location of the ATPase site of myosin determined by three-dimensional electron microscopy

Both ATP hydrolysis by myosin and the accompanying cyclic association-dissociation of actin and myosin are essential for muscle contraction. It is important for understanding the molecular mechanism of contraction to know the three-dimensional locations of the two major functional sites of myosin: the ATPase site and the actin-binding site. We have determined the position of the ATPase site of myosin using three-dimensional image reconstruction from electron micrographs and site-specific labelling with the avidin-biotin system. The ATPase site is about 5 nm from the tip of the myosin head and is about 4 nm away from the actin-binding site of myosin. This is the first report of the three-dimensional location of an enzyme active site by electron microscopy.     

PH值对应用肌球蛋白 ATP酶法进行梭内肌纤维分型的影响

探讨酸性和碱性预孵育处理，对应用肌球蛋白ATP酶法进行梭内肌纤维分型的影响。采用肌球蛋白ATP酶法。PH4．3和PH4．6预孵育液孵育后，梭内肌纤维中的核袋纤维染色呈阳性，核链纤维染色相对较浅；PH9．4预孵育后，核袋与核链纤维均呈阳性或强阳性；PH10．4预孵育后，核袋1纤维呈阴性，核袋2纤维呈阳性，核链纤维呈强阳性。结论是：用mATP酶法研究梭内肌纤维的分型时，预孵育液的PH值对分型结果有显著影响，应当说明并严格把握预孵育液的PH值。     

下肢静脉功能不全时下肢腓肠肌细胞病理生理学改变的研究

探讨腓肠肌细胞病理形态学和细胞代谢变化与下肢静脉功能不全相互关系及其临床意义 .依据血管造影和多普勒超声检查结果分为对照组 (A组 )及单纯下肢浅静脉曲张 (B组 )、原发性下肢深静脉瓣膜功能不全(C组 ) 3组 ,每组 1 0例 .分别取大腿长收肌 (对照 )和小腿腓肠肌标本检测肌肉中的SOD、NO、Na+ _K+ _ATP酶、Ca2 + _ATP酶、乳酸等各项指标 ;HE染色、ATP酶染色、SDH/COX双重染色后光镜、电镜观察 .结果显示 :A及B组肌组织结构和生化指标均正常 ,C组腓肠肌可见散在肌纤维萎缩、变性和坏死 ,炎性细胞浸润 ;同型肌纤维群化 ;COX/SDH染色可见单根或多根肌纤维酶活性增高 .肌丝间可见脂肪空泡聚集 ,部分线粒体空泡化或髓鞘样改变 .C组腓肠肌乳酸显著高于其他组别 (P <0 .0 1 ) ,而其Na_K_ATP酶、Ca2 + _ATP酶活性、NO、SOD等与其他组比较有显著下降 (P <0 .0 1 ) .表明下肢深静脉功能不全者患肢腓肠肌在肌纤维类型、超微结构和肌肉组织多项生化指标等均发生明显变化 ,推测小腿腓肠肌超微结构的病变是手术后远期效果不佳的病理基础 .如果从骨骼肌营养和抗氧化处理等角度进行治疗 ,可能会改善小腿肌肉泵功能     

Sliding distance of actin filament induced by a myosin crossbridge during one ATP hydrolysis cycle

Muscle contraction results from a sliding movement of actin filaments induced by myosin crossbridges on hydrolysis of ATP, and many non-muscle cells are thought to move using a similar mechanism. The molecular mechanism of muscle contraction, however, is not completely understood. One of the major problems is the mechanochemical coupling at high velocity under near-zero load. Here, we report measurements of the sliding distance of an actin filament induced by a myosin crossbridge during one ATP hydrolysis cycle in an unloaded condition. We used single sarcomeres from which the Z-lines, structures which anchor the thin filaments in the sarcomere, had been completely removed by calcium-activated neutral protease (CANP) and trypsin, and measured both the sliding velocity of single actin filaments along myosin filaments and the ATPase activity during sliding. Our results show that the average sliding distance of the actin filament is less than or equal to 600 A during one ATP cycle, much longer than the length of power stroke of myosin crossbridges deduced from mechanical studies of muscle, which is of the order of 80 A (for example, ref. 15).     

Movement of myosin-coated beads on oriented filaments reconstituted from purified actin

Although the biochemical properties of the actin/myosin interaction have been studied extensively using actin activation of myosin ATPase as an assay, until recently no well-defined assay has been available to measure the mechanical properties of ATP-dependent movement of myosin along actin filaments. The first direct measurements of the rate of myosin movement in vitro used a naturally occurring, biochemically ill-defined array of actin filaments from the alga Nitella. We report here the construction of an oriented array of filaments reconstituted from purified muscle actin and the use of this array in a biochemically defined quantitative assay for the directed movement of myosin-coated polystyrene beads. We demonstrate for the first time that actin alone, linked to a substratum by a protein anchor, is sufficient to support movement of myosin at rates consistent with the speeds of muscle contraction and other forms of cell motility.     

锯缘青蟹不同器官组织中4种类型ATPase活性比较研究

本实验采用生化方法研究了锯缘青蟹的鳃、肝胰腺和肌肉等不同器官组织中4种类型ATPase活性.结果表明,不同器官组织中同类型ATPase活性各异,Na K ATPase活性由强至弱为鳃>肝胰腺>肌肉.Ca2 ATPase活性为肌肉>肝胰腺>鳃.Mg2 ATPase活性为鳃>肌肉>肝胰腺.Ca2 Mg2 ATPase活性则为肌肉>鳃>肝胰腺.同一器官组织中不同类型ATPase活性也有较大的差异,鳃中Na K ATPase活性最大,其余的依次为Mg2 AT Pase,Ca2 Mg2 ATPase,Ca2 ATPase;肝胰腺中Na K ATPase活性最强,其余的依次为Ca2 Mg2 ATPase,Mg2 ATPase,Ca2 ATPase;肌肉中Ca2 Mg2 ATPase活性最大,其余的依次为Ca2 ATPase,Na K ATPase,Mg2 ATPase.此外,锯缘青蟹同一器官组织中同类型ATPase在不同个体间也存在一定差异.不同器官组织中4种类型ATPase活性各异主要与其所执行的生理功能密切相关.