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Aging impairs regulation of ryanodine receptors from extensor digitorum longus but not soleus muscles
Author(s) -
Gaboardi Angela J.,
Kressler Jochen,
Snow Teresa K.,
Balog Edward M.
Publication year - 2018
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.26063
Subject(s) - ryanodine receptor , ryr1 , medicine , skeletal muscle , endocrinology , calmodulin , endoplasmic reticulum , soleus muscle , chemistry , calcium , extensor digitorum longus muscle , muscle contraction , ageing , biology , biochemistry
Introduction : Because impaired excitation‐contraction coupling and reduced sarcoplasmic reticulum (SR) Ca 2+ 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 : [ 3 H]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 Ca 2+ and calmodulin (CaM). Results : Aging reduced maximal Ca 2+ ‐stimulated binding to EDL membranes. In 0.3 μM Ca 2+ , age reduced binding and CaM increased binding to EDL membranes. In 300 μM Ca 2+ , CaM reduced binding, but the age effect was not significant. Aging did not affect Ca 2+ or CaM regulation of soleus RyR1. Discussion : In aged fast‐twitch muscle, impaired RyR1 Ca 2+ regulation may contribute to lower SR Ca 2+ release and reduced muscle function. Muscle Nerve 57 : 1022–1025, 2018