INVESTIGATION OF GATING CURRENTS IN SKELETAL MUSCLE

将使用三个微电极电压钳技术来研究 蛙骨骼肌纤维的膜电荷运动(门控电流)。在……里面 此外，还将测量细胞内游离钙离子浓度的变化 在步骤去极化过程中，使用金属显色指示剂偶氮砷III。 染料将通过离子电泳法注入皮肤的纤维中。 胸肌。一个直径50微米的光点，来自钨-卤素 灯具将重点放在电压控制点上。光线的变化 透过率将使用复合显微镜在三个波长下测量， 分束器和干涉滤光片。一种显微镜光度测量系统，具有 已构建并测试了所需的灵敏度。该计划的目标是 研究是为了验证这样一种假设，即肌肉中的膜电荷运动是 肌浆网钙离子释放门控电流。这个 假说将通过检验电荷运动和钙离子 在不同的实验条件下，瞬变行为是平行的。为 例如，电压依赖、亚阈值响应、阈值行为和 我们将考察其对长时间去极化的反应。

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.