INVESTIGATION OF GATING CURRENTS IN SKELETAL MUSCLE

骨骼肌门控电流的研究

• 批准号: 3405577
• 负责人: ROBERT F RAKOWSKI
• 金额: $ 13.13万
• 依托单位: ROSALIND FRANKLIN UNIV OF MEDICINE & SCI
• 依托单位国家: 美国
• 财政年份: 1985
• 资助国家: 美国
• 起止时间: 1985-01-01 至 1987-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3405577
• 关键词: calcium metabolism; electrophysiology; ion transport; membrane potentials; microelectrodes; muscle contraction; neural transmission; sarcoplasmic reticulum

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.

本文将采用三微电极电压钳技术进行研究