TY - JOUR
T1 - Binding and functions of extracellular ATP in cultured cerebellar granule neurons
AU - Merlo, Daniela
AU - Volonté, Cinzia
PY - 1996/8/23
Y1 - 1996/8/23
N2 - Selected purinoceptor modulators were previously shown to prevent glutamate-evoked cytotoxicity in cerebellar granule neurons. In the same cellular system, we now identify and characterize the presence of P2 receptors. The binding of [3H]ATP to membranes of cerebellar granule neurons grows monotonically as a function of neuronal differentiation, is saturable and reaches steady state within 6 min. Scatchard plot of the equilibrium saturation data is curvilinear with a K(d) value of 28 nM and a B(max) value of 87 pmol/mg of protein for the high affinity binding sites and a K(d) value of 1.5 μM and B(max) value of 1.2 nmol/mg of protein, for the more numerous low affinity binding sites. We also show that extracellular ATP increases the release, but not the uptake, of [3H]D-aspartate and that it furthermore potentiates the release of [3H]D-aspartate evoked by glutamate and KCl. ATP itself is released by cerebellar granule cultures and such release grows monotonically as a function of neuronal differentiation. These data are consistent with the role that ATP is believed to play as a cotransmitter for the central nervous system.
AB - Selected purinoceptor modulators were previously shown to prevent glutamate-evoked cytotoxicity in cerebellar granule neurons. In the same cellular system, we now identify and characterize the presence of P2 receptors. The binding of [3H]ATP to membranes of cerebellar granule neurons grows monotonically as a function of neuronal differentiation, is saturable and reaches steady state within 6 min. Scatchard plot of the equilibrium saturation data is curvilinear with a K(d) value of 28 nM and a B(max) value of 87 pmol/mg of protein for the high affinity binding sites and a K(d) value of 1.5 μM and B(max) value of 1.2 nmol/mg of protein, for the more numerous low affinity binding sites. We also show that extracellular ATP increases the release, but not the uptake, of [3H]D-aspartate and that it furthermore potentiates the release of [3H]D-aspartate evoked by glutamate and KCl. ATP itself is released by cerebellar granule cultures and such release grows monotonically as a function of neuronal differentiation. These data are consistent with the role that ATP is believed to play as a cotransmitter for the central nervous system.
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U2 - 10.1006/bbrc.1996.1271
DO - 10.1006/bbrc.1996.1271
M3 - Article
C2 - 8780710
AN - SCOPUS:0030598893
VL - 225
SP - 907
EP - 914
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 3
ER -