M. Oike et Y. Ito, DYNAMIC REGULATION OF INTRACELLULAR CA2-CELLS( CONCENTRATION IN AORTIC ENDOTHELIAL), European journal of pharmacology, 319(2-3), 1997, pp. 291-298
In non-excitable cells, a Ca2+ entry pathway is opened after the deple
tion of intracellular Ca2+ store sites. We have tried to estimate the
sensitivity of this pathway to Ca2+ release using bovine aortic endoth
elial cells. Single application of a high concentration (30 mu M) of A
TP released almost all stored Ca2+ in Ca2+-free extracellular solution
, whereas a low concentration of ATP (30 nM) produced a partial (57.3
+/- 3.0%) release of Ca2+. By 10 min of Ca2+ re-perfusion, the Ca2+ st
ore site was reloaded to 97.1% of its initial filling state. When thap
sigargin was applied to this cell in Mn2+ solution, Mn2+-induced quenc
hing of fura-2 dye started when 19.3 +/- 5.3% of Ca2+ release, produce
d by 30 nM ATP, had occurred. Therefore, Ca2+ release required for Mn2
+ entry was estimated as 11.1 +/- 3.0% of stored Ca2+. These results i
ndicate that intracellular Ca2+ concentration is controlled dynamicall
y by simultaneously occurring Ca2+ release and entry in bovine aortic
endothelial cells.