AGING IMPAIRS REGULATION OF RYANODINE RECEPTORS FROM EXTENSOR DIGITORUM LONGUS BUT NOT SOLEUS MUSCLES

作者：Gaboardi Angela J; Kressler Jochen; Snow Teresa K; Balog Edward M^*

来源：Muscle & Nerve, 2018, 57(6): 1022-1025.

DOI：10.1002/mus.26063

• aging
• calcium
• calmodulin
• excitation-contraction coupling
• ryanodine receptor
• sarcoplasmic reticulum
• skeletal muscle

Introduction: Because impaired excitation-contraction coupling and reduced sarcoplasmic reticulum (SR) Ca2+ release may contribute to the age-associated decline in skeletal muscle strength, we investigated the effect of aging on regulation of the skeletal muscle isoform of the ryanodine receptor (RyR1) by physiological channel ligands. Methods: [H-3]Ryanodine binding to membranes from 8- and 26-month-old Fischer 344 extensor digitorum longus (EDL) and soleus muscles was used to investigate the effects of age on RyR1 modulation by Ca2+ and calmodulin (CaM). Results: Aging reduced maximal Ca2+-stimulated binding to EDL membranes. In 0.3 mu M Ca2+, age reduced binding and CaM increased binding to EDL membranes. In 300 mu M Ca2+, CaM reduced binding, but the age effect was not significant. Aging did not affect Ca2+ or CaM regulation of soleus RyR1. Discussion: In aged fast-twitch muscle, impaired RyR1 Ca2+ regulation may contribute to lower SR Ca2+ release and reduced muscle function.

• 出版日期2018-6