Acute Elevated Glucose Promotes Abnormal Action Potential-Induced Ca2+ Transients in Cultured Skeletal Muscle Fibers
JournalJournal of Diabetes Research
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AbstractA common comorbidity of diabetes is skeletal muscle dysfunction, which leads to compromised physical function. Previous studies of diabetes in skeletal muscle have shown alterations in excitation-contraction coupling (ECC) - the sequential link between action potentials (AP), intracellular Ca2+ release, and the contractile machinery. Yet, little is known about the impact of acute elevated glucose on the temporal properties of AP-induced Ca2+ transients and ionic underlying mechanisms that lead to muscle dysfunction. Here, we used high-speed confocal Ca2+ imaging to investigate the temporal properties of AP-induced Ca2+ transients, an intermediate step of ECC, using an acute in cellulo model of uncontrolled hyperglycemia (25 mM, 48 h.). Control and elevated glucose-exposed muscle fibers cultured for five days displayed four distinct patterns of AP-induced Ca2+ transients (phasic, biphasic, phasic-delayed, and phasic-slow decay); most control muscle fibers show phasic AP-induced Ca2+ transients, while most fibers exposed to elevated D-glucose displayed biphasic Ca2+ transients upon single field stimulation. We hypothesize that these changes in the temporal profile of the AP-induced Ca2+ transients are due to changes in the intrinsic excitable properties of the muscle fibers. We propose that these changes accompany early stages of diabetic myopathy. Copyright 2017 Erick O. Hernández-Ochoa et al.
SponsorsThis work was supported by NIH Grant R37-AR055099 to Martin F. Schneider from the National Institute of Arthritis and Musculoskeletal and Skin Diseases.
KeywordAction Potentials--drug effects
Calcium Signaling--drug effects
Excitation Contraction Coupling--drug effects
Mice, Inbred C57BL
Muscle Fibers, Skeletal--drug effects
Muscle Fibers, Skeletal--metabolism
Identifier to cite or link to this itemhttps://www.scopus.com/inward/record.uri?eid=2-s2.0-85042743525&doi=10.1155%2f2017%2f1509048&partnerID=40&md5=53529a6ad2ad5a52972d8177c060f936; http://hdl.handle.net/10713/11004