Inhibition by imipramine of ATP-evoked responses in rat pheochromocytoma cells.
The effect of imipramine on the ATP-evoked release of dopamine was analyzed in parallel with its effects on the rise in the intracellular Ca2+ concentration ([Ca2+]i) and current induced by ATP in rat pheochromocytoma PC12 cells. Imipramine (10-300 microM) inhibited the ATP-evoked release of dopamine and rise in [Ca2+]i in a concentration-dependent fashion though the effect of imipramine on the release was slightly more obvious. Imipramine also inhibited the ATP-activated inward current at a similar concentration range. These results show a new pharmacological profile of imipramine, namely the inhibition of P2X2 receptors.
Koizumi
S
S
Division of Pharmacology, National Institute of Health Sciences, Tokyo, Japan.
Uneyama
H
H
Ikeda
M
M
Ueno
S
S
Inoue
K
K
D000255:Adenosine Triphosphate / Q000494:pharmacology*; D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D002147:Calmodulin / Q000037:antagonists & inhibitors; D004298:Dopamine / Q000378:metabolism*; D007099:Imipramine / Q000494:pharmacology*; D007424:Intracellular Fluid / Q000378:metabolism; D017136:Ion Transport / Q000187:drug effects; D008564:Membrane Potentials / Q000187:drug effects; D016716:PC12 Cells; D058919:Purinergic P2 Receptor Antagonists; D051381:Rats; D058476:Receptors, Purinergic P2X2
D000929:Antidepressive Agents, Tricyclic; D002147:Calmodulin; C546403:P2rx2 protein, rat; D058919:Purinergic P2 Receptor Antagonists; D058476:Receptors, Purinergic P2X2; D000255:Adenosine Triphosphate; D007099:Imipramine; D002118:Calcium; D004298:Dopamine