G. Arslan et al., P2Y receptors contribute to ATP-induced increases in intracellular calciumin differentiated but not undifferentiated PC12 cells, NEUROPHARM, 39(3), 2000, pp. 482-496
ATP-induced Ca2+ transients were examined in individual PC12 cells of a wel
l defined clone, before and after treatment with nerve growth factor (NGF)
to induce a neurone-like phenotype. Using reverse transcriptase PCR these c
ells were found to express mRNA for several PZ receptors, In undifferentiat
ed cells the ATP-induced Ca2+ response was entirely dependent on Ca2+ influ
x, could nor be mimicked by UTP, alpha,beta-methylene ATP or dibenzoyl ATP
or be blocked by pyridoxalphosphate-6-azophenyl-2',4'-disulphonic acid (PPA
DS). ATP had no significant effect on levels of cyclic AMP or inositol 1,4,
5-trisphosphate (InsP(3)). These results suggest that in undifferentiated P
C12 cells ATP mainly acts on a P2X receptor, possibly the P2X(4) subtype, A
fter treatment with NGF for 7 days the ATP response was increased and parti
ally sensitive to PPADS, A component of the ATP-induced Ca2+ increase was d
ue to mobilisation of intracellular Ca2+ stores and another to capacitative
Ca2+ entry, UTP caused an increase in intracellular Ca2+, and InsP(3) form
ation could be stimulated by ATP and UTP, ATP also caused a small increase
in cyclic AMP, but this was abolished in the presence of indomethacin. Thus
, after NGF treatment ATP acts partially via a P2Y receptor, possibly the P
2Y(2) subtype. (C) 2000 Elsevier Science Ltd. All rights reserved.