Changes in the mechanism of Ca2(+) mobilization during the differentiation of BC3H1 muscle cells.
Ca2+ sequestration and release in BC3H1 muscle cells is strongly dependent on the stage of differentiation. In proliferating cells, more than 90% of the sequestered Ca2+ was Ins(1,4,5)P3-sensitive and 25% was caffeine-sensitive. In differentiated cells, the Ca2+ accumulation was 5-fold higher and was InsP3-insensitive, but about 60% of the sequestered Ca2+ was caffeine-sensitive. These changes were reversible upon addition of growth stimuli. Similarly, by measuring the intracellular Ca2+ concentration in single intact BC3H1 cells, it was found that the number of histamine-responsive cells decreased and the number of caffeine-responsive cells increased during muscle cell differentiation. These data indicate that the development of the muscle phenotype in BC3H1 myoblasts induces a major rearrangement of the mechanisms for Ca2+ mobilization.
De Smedt
H
H
Laboratorium voor Fysiologie, Campus Gasthuisberg, Katholieke Universiteit Leuven, Belgium.
Parys
J B
JB
Himpens
B
B
Missiaen
L
L
Borghgraef
R
R
D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism*; D002454:Cell Differentiation; D002460:Cell Line; D007295:Inositol Phosphates / Q000494:pharmacology; D051379:Mice; D009132:Muscles / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism
D007295:Inositol Phosphates; D002110:Caffeine; D002118:Calcium