Ca2+ signalling pathways activated by acetylcholine in mouse C2C12 myotubes.
In mouse C2C12 myotubes acetylcholine (ACh) elevates the concentration of myoplasmic Ca2+ ([Ca2+]i) by inducing Ca2+ influx through transmitter-gated and voltage-gated channels, and by mobilizing Ca2+ from internal stores. The relative contribution of each of these ACh-activated sources to the global [Ca2+]i elevation was estimated. We found that Ca2+ entry through voltage- and ACh-gated channels accounts for roughly 80% of the total [Ca2+]i increment, while mobilization from internal caffeine-sensitive and inositoltrisphosphate- (InsP3-) sensitive stores contributes the remaining 20% to the maximal [Ca2+]i increment. Furthermore, we found that ACh-induced mobilization from InsP3-sensitive stores also develops in embryonic chick myotubes. The differential importance of the Ca2+ signalling pathways activated by ACh during myogenesis is discussed.
Grassi
F
F
Dipartimento di Medicina Sperimentale, Università di Roma La Sapienza, Italy.
Fucile
S
S
Eusebi
F
F
D000109:Acetylcholine / Q000494:pharmacology*; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D002642:Chick Embryo; D004594:Electrophysiology; D005110:Extracellular Space / Q000378:metabolism; D015544:Inositol 1,4,5-Trisphosphate / Q000494:pharmacology; D015640:Ion Channel Gating; D007473:Ion Channels / Q000037:antagonists & inhibitors; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000166:cytology / Q000378:metabolism*; D018733:Nicotinic Antagonists; D015398:Signal Transduction / Q000187:drug effects*
D007473:Ion Channels; D018733:Nicotinic Antagonists; D002110:Caffeine; D015544:Inositol 1,4,5-Trisphosphate; D000109:Acetylcholine; D002118:Calcium