title: Adenosine enhances intracellular Ca2+ mobilization in conjunction with metabotropic glutamate receptor activation by t-ACPD in cultured hippocampal astrocytes.
abstract: 2Cl-Adenosine, a non-metabolized adenosine agonist, enhanced the increase in intracellular Ca2+ concentration ([Ca2+]i) in cultured hippocampal astrocytes induced by (+-)-1-aminocyclopentane-trans-1,3-dicarboxylic acid (t-ACPD), a metabotropic glutamate agonist. In the absence of 2Cl-adenosine, the half effective concentration (EC50) of t-ACPD was about 80 microM. On the other hand, in the presence of 1 microM 2Cl-adenosine, the EC50 of t-ACPD shifted to about 5 microM, although the maximum [Ca2+]i did not change. The synergistic effect of 2Cl-adenosine with t-ACPD on [Ca2+]i elevation was not inhibited by the elimination of extracellular Ca2+, but was inhibited by A1-specific adenosine antagonists. These results indicate that adenosine can act via the A1 receptor as an endogenous co-activator of the metabolic processes induced by metabotropic glutamate receptor activation.
authors.affiliation: Department of Physiology, Ehime University School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Ogata
authors.forename: Y
authors.initials: Y
authors.lastname: Nakamura
authors.forename: K
authors.initials: K
authors.lastname: Tsuji
authors.forename: T
authors.initials: T
authors.lastname: Shibata
authors.forename: K
authors.initials: K
authors.lastname: Kataoka
authors.forename: P
authors.initials: P
authors.lastname: Schubert
mesh_terms: D000241:Adenosine / Q000494:pharmacology*; D000818:Animals; D001253:Astrocytes / Q000187:drug effects / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D003515:Cycloleucine / Q000031:analogs & derivatives* / Q000494:pharmacology; D004357:Drug Synergism; D006624:Hippocampus / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D009498:Neurotoxins / Q000494:pharmacology*; D058915:Purinergic P1 Receptor Antagonists; D051381:Rats; D018094:Receptors, Metabotropic Glutamate / Q000187:drug effects / Q000378:metabolism*
chemical_list: D009498:Neurotoxins; D058915:Purinergic P1 Receptor Antagonists; D018094:Receptors, Metabotropic Glutamate; D003515:Cycloleucine; C036361:1-amino-1,3-dicarboxycyclopentane; D000241:Adenosine; D002118:Calcium