MECHANICAL PROPERTIES OF SMOOTH MUSCLE .2. ACTIVE STATE
MECHANICAL PROPERTIES OF SMOOTH MUSCLE .2. ACTIVE STATE
复制标题
DOI：
10.1152/ajplegacy.1971.221.5.1250
复制
发表时间：
1971-01-01
影响因子：
--
通讯作者：
SIEGMAN, MJ
中科院分区：
文献类型：
--
作者：
GORDON, AR;SIEGMAN, MJ
方法组织和溶液的制备。参考文献9a中描述了用于力学研究的兔结肠带节段的制备。在本研究中遵循相同的程序。在Z-hr平衡期之后，如随附论文中所述确定最佳肌肉长度I1。该装置的布置使得肌肉的一端固定到等距力传感器（Grass FT-10），另一端固定到大电流计（Grass电流计）的电枢轴。使用两个测微计挡块来调整肌肉长度或限制电枢的偏移。Hill（12）的快速拉伸技术用于确定活性状态的时间过程。简单地说，这种方法包括在单次电击后对肌肉进行快速拉伸。从两个铂-氯化铂电极对肌肉进行电刺激，电极放置在两侧相距5 mm并平行于肌肉条的纵轴。通过从恒流源（Grass CCU-1）向电枢线圈通入直流电流，实现快速拉伸（平均2 mm/组）。通过调节测微计挡块的位置来改变拉伸量，并且通过改变驱动电流计的计时装置上的延迟来改变施加拉伸的时间。按照Hill的规定，在每次测定前进行100次电击（12）。在施加单次超大直流电电击（6-9 V，5-10 msec持续时间）后，以预设的间隔拉伸肌肉，直到电击后拉伸产生水平运行3-5组的张力，然后向基线张力衰减（即，长度为lo的被动张力）。增加电击和拉伸之间的间隔，并重复该过程以获得活动状态的时间过程。所有实验均在22 ℃下进行，以消除自发活动（9）。统计分析每种材料的张力和时间数据
METHODSPreparation of tissues and solutions. The preparation of rabbit taenia coli segments for the mechanical studies was described in ref. 9a. Identical procedures were followed in this study.Experimental procedures. Following a Z-hr equilibration period, the optimum muscle length, I,, was determined as described in the accompanying paper. The arrangement of the apparatus was such that one end of the muscle was secured to an isometric force transducer(Grass FT-10) and the other to the armature shaft of a large galvanometer (Grass oscillograph). Two micrometer stops were used to adjust the muscle length or limit the excursion of the armature. The quick-stretch technique of Hill (12) was used to determine the time course of the active state. Briefly, this method involves the application of a quick stretch to the muscle following a single shock. The muscles were electrically stimulated from two platinum-platinum chloride electrodes placed 5 mm apart on either side and parallel to the longitudinal axis of the muscle strip. The quick stretch (averaging 2 mm/set) was imposed by passing a dc current through the armature coil from a constant-current source (Grass CCU-1). The amount of stretch was varied by adjusting the position of the micrometer stops and the time of application of the stretch by varying the delay on a timing device which drove the galvanometer. Three shocks were delivered 100 set before each determination, as prescribed by Hill (12). At preset intervals after the application of a single supramaximal dc shock (6-9 v, 5-10 msec duration), the muscle was stretched until following the shock the stretch produced a tension which ran horizontally for 3-5 set before decaying toward the base-line tension (ie, the passive tension at length lo). The interval between the shock and the stretch was increased and the procedure repeated to obtain the time course of the active state. All experiments were done at 22 C in order to eliminate spontaneous activity (9). Statistical analysis. The tension and time data for each