2′, 3′-O-(4-benzoylbenzoyl)–ATP-mediated calcium signaling in rat glioma C6 cells: role of the P2Y2 nucleotide receptor

摘要

In this study, we examined the response of glioma C6 cells to 2′,3′-O-(4-benzoylbenzoyl)-ATP (BzATP) and showed that the BzATP-induced calcium signaling does not involve the P2X₇ receptor activity. We show here that in the absence of extracellular Ca2+, BzATP-generated increase in [Ca2+]_ivia Ca2+ release from intracellular stores. In the presence of calcium ions, BzATP established a biphasic Ca2+ response, in a manner typical for P2Y receptors. Brilliant Blue G, a selective antagonist of the rat P2X₇ receptor, did not reduce any of the two components of the Ca2+ response elicited by BzATP. Periodate-oxidized ATP blocked not only BzATP- but also UTP-induced Ca2+ elevation. Moreover, BzATP did not open large transmembrane pores. What is more, a cross-desensitization between UTP and BzATP occurred, which clearly shows that in glioma C6 cells BzATP activates most likely the P2Y₂ but not the P2X₇ receptors.