Activation of adenosine A2 receptors enhances high K(+)-evoked taurine release from rat hippocampus: a microdialysis study.
The present study was designed to examine which type of adenosine receptors was involved in enhancement of high K(+)-evoked taurine release from in vivo rat hippocampus using microdialysis. Perfusion with 0.5 or 5.0 mM adenosine enhanced high K(+)-evoked taurine release. Perfusion with 2 microM R(-)-N6-2-phenylisopropyladenosine (PIA), a selective adenosine A1 receptor agonist, did not modulate taurine release. Perfusion with 1 microM 1,3-dipropyl-8-cyclopentylxanthine (DPCPX), a selective adenosine A1 receptor antagonist, increased taurine release. On the other hand, perfusion with 20 microM 2-[4-(2-carboxyethyl)phenethylamino]-5'-N-ethyl-carboxamide-adenos ine (CGS21680), a selective adenosine A2A receptor agonist, enhanced taurine release, while perfusion with 1 mM 3,7-dimethyl-propagylxanthine (DMPX), an adenosine A2 receptor antagonist, did not affect taurine release. These results demonstrate that adenosine enhances high K(+)-evoked taurine release via activation of adenosine A2A receptors from both neurons and glial cells of in vivo rat hippocampus.
Hada
J
J
Department of Physiology, Hyogo College of Medicine, Japan.
Kaku
T
T
Morimoto
K
K
Hayashi
Y
Y
Nagai
K
K
D000241:Adenosine / Q000494:pharmacology*; D000818:Animals; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D017551:Microdialysis; D010477:Perfusion; D011188:Potassium / Q000494:pharmacology*; D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D051381:Rats; D017208:Rats, Wistar; D018047:Receptors, Purinergic P1 / Q000378:metabolism*; D013654:Taurine / Q000378:metabolism*
D058906:Purinergic P1 Receptor Agonists; D058915:Purinergic P1 Receptor Antagonists; D018047:Receptors, Purinergic P1; D013654:Taurine; D000241:Adenosine; D011188:Potassium