TY - JOUR
T1 - Dual modulation by adenosine of ATP-activated channels through GTP-binding proteins in rat pheochromocytoma PC12 cells
AU - Inoue, Kazuhide
AU - Watano, Tomokazu
AU - Koizumi, Shuichi
AU - Nakazawa, Ken
AU - Burnstock, Geoffrey
PY - 1994/7/15
Y1 - 1994/7/15
N2 - Effects of adenosine on inward current activated by extracellular ATP were examined in rat pheochromocytoma PC12 cells. Adenosine induced two types of modulation on the current activated by 30 μM ATP; a low concentration of adenosine (1 μM) inhibited the current whereas a high concentration (>10 μM) enhanced the current. Neither the inhibition nor the enhancement was observed in cells pretreated with pertussis toxin (PTX), or in cells dialyzed with guanosine 5′-O-(2-thiotriphosphate) trilithium salt (GDPβS). In contrast, dialysis with K-252a, a protein kinase inhibitor, abolished the inhibition, but not the enhancement. Adenosine induced similar inhibition and enhancement on ATP-evoked increase in intracellular free Ca2+ concentration. The results suggest that adenosine produces dual modulation on the ATP-activated channels through different mechanisms involving PTX-sensitive GTP-binding proteins.
AB - Effects of adenosine on inward current activated by extracellular ATP were examined in rat pheochromocytoma PC12 cells. Adenosine induced two types of modulation on the current activated by 30 μM ATP; a low concentration of adenosine (1 μM) inhibited the current whereas a high concentration (>10 μM) enhanced the current. Neither the inhibition nor the enhancement was observed in cells pretreated with pertussis toxin (PTX), or in cells dialyzed with guanosine 5′-O-(2-thiotriphosphate) trilithium salt (GDPβS). In contrast, dialysis with K-252a, a protein kinase inhibitor, abolished the inhibition, but not the enhancement. Adenosine induced similar inhibition and enhancement on ATP-evoked increase in intracellular free Ca2+ concentration. The results suggest that adenosine produces dual modulation on the ATP-activated channels through different mechanisms involving PTX-sensitive GTP-binding proteins.
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U2 - 10.1016/0922-4106(94)90192-9
DO - 10.1016/0922-4106(94)90192-9
M3 - Article
C2 - 7525318
AN - SCOPUS:0028169074
SN - 0922-4106
VL - 268
SP - 223
EP - 229
JO - European Journal of Pharmacology - Molecular Pharmacology Section
JF - European Journal of Pharmacology - Molecular Pharmacology Section
IS - 2
ER -