Intra- and intercellular calcium signaling in human neuroepithelioma cells.
The characteristics of intra- and intercellular Ca2+ signaling in human SK-N-MCIXC neuroepithelioma cells have been examined by means of Fura-2 digital imaging microfluorimetry. When cells were exposed to maximally effective concentrations of either endothelin-1, ATP, norepinephrine or oxotremorine-M, the Ca2+ signals that accompany an increase in phosphoinositide turnover could be differentiated on the basis of their magnitude, shape and duration. When individual cells were microinjected with inositol 1,4,5-trisphosphate, a rise in [Ca2+]i was observed not only in the target cell, but also in neighboring cells. This intercellular propagation of Ca2+ signals was found to be mediated via the release of nucleotide di- and triphosphates which subsequently activate purinergic receptors linked to Ca2+ homeostasis on neighboring cells. These results indicate: (1) that agonist-specific Ca2+ 'signatures' are generated in SK-N-MCIXC cells; and (2) that an intercellular propagation of Ca2+ signals is triggered by a rise in [Ca2+]i.
Department of Pharmacology, University of Michigan, Ann Arbor 48109-0632, USA.
R K
RK
Palmer
D I
DI
Yule
E L
EL
McEwen
J A
JA
Williams
S K
SK
Fisher
D002118:Calcium / Q000378:metabolism*; D002460:Cell Line; D005456:Fluorescent Dyes; D016257:Fura-2; D006801:Humans; D018241:Neuroectodermal Tumors, Primitive, Peripheral / Q000378:metabolism*; D015398:Signal Transduction
D005456:Fluorescent Dyes; D002118:Calcium; D016257:Fura-2