Extracellular ATP elevates cytoplasmatic free Ca2+ in HeLa cells by the interaction with a 5'-nucleotide receptor.
In the present study we have characterized the effects of ATP and several other nucleotides on the intracellular Ca2+ levels of HeLa cells. Using fura-2 microscopy fluorescence measurements, the ATP-mediated increase in intracellular Ca2+ was shown to consist of a rapid rise which decreased after a few seconds to a sustained elevated level. In the absence of extracellular Ca2+ or in the presence of 10 microM La3+, only a transient elevation of the Ca2+ concentration was observed. The ATP responses were not altered after treatment of HeLa cells with cholera toxin or pertussis toxin. Pharmacological analysis of this calcium response revealed that this effect was not mediated by the classical P2y purinoceptor but by a 5'-nucleotide receptor.
Smit
M J
MJ
Leiden/Amsterdam Center for Drug Research, Division of Molecular Pharmacology, The Netherlands.
Leurs
R
R
Bloemers
S M
SM
Tertoolen
L G
LG
Bast
A
A
De Laat
S W
SW
Timmerman
H
H
D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism*; D002772:Cholera Toxin / Q000494:pharmacology; D003593:Cytoplasm / Q000187:drug effects / Q000378:metabolism*; D016257:Fura-2; D019204:GTP-Binding Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D037342:Pertussis Toxin; D018048:Receptors, Purinergic P2 / Q000187:drug effects / Q000378:metabolism*; D014544:Uridine Triphosphate / Q000494:pharmacology; D010566:Virulence Factors, Bordetella / Q000494:pharmacology
D018048:Receptors, Purinergic P2; D010566:Virulence Factors, Bordetella; D000255:Adenosine Triphosphate; D002772:Cholera Toxin; D037342:Pertussis Toxin; D019204:GTP-Binding Proteins; D002118:Calcium; D016257:Fura-2; D014544:Uridine Triphosphate