INHIBITION BY IMIPRAMINE OF ATP-EVOKED RESPONSES IN RAT PHEOCHROMOCYTOMA CELLS

The effect of imipramine on the ATP-evoked release of dopamine was ana lyzed in parallel with its effects on the rise in the intracellular Ca 2+ concentration ([Ca2+](i)) and current induced by ATP in rat pheochr omocytoma PC12 cells, Imipramine (10-300 mu M) inhibited the ATP-evoke d release of dopamine and rise in [Ca2+](i) in a concentration-depende nt fashion though the effect of imipramine on the release was slightly more obvious, Imipramine also inhibited the ATP-activated inward curr ent at a similar concentration range, These results show a new pharmac ological profile of imipramine, namely the inhibition of P2X(2) recept ors. (C) 1998 Academic Press.