Nielsen-Kudsk F, Poulsen B, Ryom C, Nielsen-Kudsk J E
J Pharmacol Methods. 1986 Nov;16(3):215-25. doi: 10.1016/0160-5402(86)90043-4.
Isometric tension measurements in vitro on small vessels are important in studies of pharmacodynamic vascular effects of drugs and autacoids. The present study describes a precision myograph equipped with a newly constructed highly isometric strain-gauge transducer used in conjunction with a very sensitive, low-noise and virtually drift-free dc-amplifier. The isometric quotient of the transducer, defined as deflection in micrometer per g of force, is about 5.2. The transducer resonance frequency is 341 c/sec with a damping constant of 1.05. The highest sensitivity of the transducer in connection with the matching dc-amplifier is about 170 mV/V/g force. The practical working range of the myograph is from 2 mg to about 10 g of applied tensile force. Tubular segments of vessels with internal diameters down to 150 micron can be mounted in the myograph on two stainless-steel pins submerged in a 5 ml preparation bath. Precise mounting and setting of passive (resting) tension is assured by the use of micrometer-equipped adjustable miniature mounting tables suspended by roller bearings. The myograph may be provided with electrodes for field-effect stimulation of the vessel preparations. Other muscle preparations may also be mounted in the myograph. Application of the myograph in studies on rabbit coronary arteries is demonstrated by a length-tension diagram obtained in experiments with tubular segments (inner diameter about 500 micron) of the circumflex branch on the left coronary artery, which shows a typical course in development of active and passive tension of the smooth musculature when exposed to alternating potassium depolarization and increasing mechanical stretching. The potassium contracture of the coronary vessels and the log-concentration/response relationship at accumulating potassium concentrations were also investigated.
在体外对小血管进行等长张力测量，对于研究药物和自分泌物质的药效学血管效应非常重要。本研究描述了一种精密肌动描记器，它配备了一个新构建的高度等长应变片式传感器，并与一个非常灵敏、低噪声且几乎无漂移的直流放大器配合使用。该传感器的等长系数，定义为每克力产生的微米级偏转，约为5.2。传感器的共振频率为341次/秒，阻尼常数为1.05。该传感器与匹配的直流放大器连接时的最高灵敏度约为170 mV/V/g力。肌动描记器的实际工作范围是施加的拉伸力从2毫克到约10克。内径小至150微米的血管管状段可以安装在肌动描记器中，置于浸没在5毫升制备浴中的两个不锈钢销上。通过使用由滚柱轴承悬挂的配备微米计的可调微型安装台，确保了被动（静息）张力的精确安装和设定。肌动描记器可以配备用于对血管制剂进行场效应刺激的电极。其他肌肉制剂也可以安装在肌动描记器中。通过在左冠状动脉回旋支的管状段（内径约500微米）实验中获得的长度-张力图，展示了肌动描记器在兔冠状动脉研究中的应用，该图显示了在交替进行钾去极化和增加机械拉伸时，平滑肌组织主动和被动张力发展的典型过程。还研究了冠状血管的钾挛缩以及在累积钾浓度时的对数浓度/反应关系。
