INHIBITION BY HETEROLOGOUSLY-EXPRESSED P2Y(2) NUCLEOTIDE RECEPTORS OFN-TYPE CALCIUM CURRENTS IN RAT SYMPATHETIC NEURONS

The P2Y(2) nucleotide receptor has previously been shown to stimulate phosphoinositide breakdown. We now show that, when P2Y(2) receptors ar e heterologously expressed by cRNA injection into dissociated rat symp athetic neurones, activation of these receptors by uridine 5'-triphosp hate (UTP) or adenosine 5'-triphosphate (ATP) inhibits the N-type volt age-gated calcium current by similar to 65%, with an IC50 of 0.5 mu M. Thus, the same molecular species of nucleotide receptor can link to t wo different effector pathways.