INVESTIGATION OF GATING CURRENTS IN SKELETAL MUSCLE

将采用三微电极电压钳技术进行研究 青蛙骨骼肌纤维的膜电荷运动（门控电流）。 在 此外，还将测定细胞内游离钙离子浓度的变化 在使用金属变色指示剂染料偶氮胂III的阶跃去极化期间。 将染料通过离子电渗法注射到皮肤的纤维中， 胸肌 一个50微米直径的光点从钨卤素灯 将灯的电压控制点集中。 的光的变化 使用复合显微镜在三个波长下测量透射率， 分束器和干涉滤光器。 一种显微镜光度计系统， 所需的灵敏度已经构建和测试。 的目的 研究的目的是检验肌肉中的膜电荷运动是一种 肌浆网释放钙离子的门控电流。 的 假设将检验是否电荷运动和钙离子 在各种实验条件下，瞬态行为是并行的。 为 例如，电压依赖性、亚阈值响应、阈值行为和 将检查对延长的去极化的响应。

The three microelectrode voltage clamp technique will be used to investigate membrane charge movement (gating current) in frog skeletal muscle fibers. In addition, the intracellular free Ca 2 ion concentration change will be measured during step depolarizations using the metallochromic indicator dye arsenazo III. The dye will be injected iontophoretically into fibers in the cutaneous pectoris muscle. A 50 microsm diameter spot of light from a tungsten-halogen lamp will be focused on the point of voltage control. Changes in light transmittance will be measured at three wavelengths using a compound microscope, beam splitters and interference filters. A microscope photometer system with the required sensitivity has been constructed and tested. The objective of the research is to test the hypothesis that membrane charge movement in muscle is a gating current for Ca 2 ion release from the sarcoplasmic reticulum. The hypothesis will be tested by examining whether charge movement and the Ca 2 ion transient behave in parallel during a variety of experimental conditions. For example, the voltage dependence, subthreshold response, threshold behavior and the response to prolonged depolarization will be examined.