Involvement of Mg2+ in terminating Ca2+ release in cultured rat skeletal muscle

FEBS Letters

Suda, Norio¹ 

[1] Max-Planck-Institut für Biophysikalische Chemie, Am Fassberg 37077 Göttingen, Germany

关键词: Skeletal muscle;    Excitation-contraction coupling;    Ryanodine receptor;    Ca2+ release channel;    Caffeine;    Fura-2;    SR;    sarcoplasmic reticulum;    T-tubule;    transverse tubule;    RyR;    ryanodine receptor;    RISC;    repolarization-induced stop of caffeine-induced Ca2+ release;    DHPR;    dihydropyridine receptor;    TTX;    tetrodotoxin;    EGTA;    ethylene-glycol-bis-N;    N;    N′;    N′ tetraacetic acid;    HEPES;    N-2-hydroxyethyl-piperazine-N′-2-ethansulphonic acid;   

DOI  :  10.1016/0014-5793(95)00047-D

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Combined patch-clamp and fura-2 measurements were performed to investigate the mechanism that terminates Ca²⁺ release in rat skeletal myoballs. When cells were intracellularly perfused with solution containing 1 mM free Mg²⁺, the caffeine (10 mM)-induced Ca²⁺ transient was abruptly terminated by membrane repolarization (−70 mV). With low intracellular Mg²⁺ (e.g. 50 μM) perfusion, however, repolarization failed to terminate the caffeine transient. The results show that intracellular Mg²⁺ is necessary for repolarization-induced closing of the Ca²⁺ release channel.

【 授权许可】

Unknown