Two subtypes of G protein-coupled nucleotide receptors, P2Y_1 and P2Y_2 are involved in calcium signalling in glioma C6 cells

摘要

In glioma C6 cells, the stimulation of P2Y receptors by ADP, ATP and UTP initiated an increase in the intracellular Ca~2+ concentration, in a process that involved the release of Ca~2+ from InsP_3-sensitive store and the capacitative, extracellular Ca~2+ entry. The presence of external Ca~2+ Was not necessary to elevate Ca~2+. The rank order of potencies of nucleotide analgoues in simulating[Ca~2+]_i was: 2MeSADP > ADP > 2MeSATP > ATP UTP α,β-Methylene ATP, adenosine and AMP were In effective ADP and UTP effects were additive, while actions of ATP and UTP were not additive on [Ca~2+] Increase. Similarly, cross-desensitization between ATP and UTP but not between ADP and UTP Occurred. Suramin, a non-specific nucleotide receptors inhibitor, antagonized ATP-, UTP-and ADP- Evoked Ca~2+ responses.