Store-operated calcium entry in differentiated C2C12 skeletal muscle cells.
In this paper, we show further evidences for the existence of store-operated calcium entry in differentiated skeletal muscle C2C12 myotubes after Ca2+ depletion in sarcoplasmic reticulum, using thapsigargin, a potent sarcoplasmic reticulum Ca2+-ATPase inhibitor, caffeine as ryanodine receptor activator, and ATP which activates purinergic receptors. The quenching of fura 2 fluorescence emission by Mn2+ also provided evidences for store-operated calcium entry because this quenching was accelerated when sarcoplasmic reticulum was depleted of Ca2+. Ca2+ entry was sensitive to Ni2+, La3+, Gd3+ and 2-aminoethyl diphenyl borate but resistant to nifedipine, thus excluding L-type Ca2+ channels in this type of calcium entry. Our data obtained using ATP for store depletion suggest that the level of Ca2+ in internal stores could play a role in the regulation of store-operated calcium channel activity in this cell type.
Gutierrez-Martin
Yolanda
Y
Departamento de Bioquimica y Biologia Molecular y Genetica, Facultad de Ciencias, Universidad de Extremadura, 06071-Badajoz, Spain.
Martin-Romero
Francisco Javier
FJ
Henao
Fernando
F
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D000697:Central Nervous System Stimulants / Q000494:pharmacology; D006801:Humans; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000378:metabolism; D018482:Muscle, Skeletal / Q000166:cytology / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D000697:Central Nervous System Stimulants; D002110:Caffeine; D000255:Adenosine Triphosphate; D002118:Calcium