Inhibition of cAMP accumulation by intracellular calcium mobilization in C6-2B cells stably transfected with substance K receptor cDNA.
C6-2B rat glioma cells were stably transfected with substance K receptor cDNA and used to study interactions between cAMP and Ca2+ signaling pathways. Activation of the newly expressed receptors by substance K increased the intracellular free Ca2+ concentration, as monitored by single-cell fura-2 imaging, and markedly inhibited agonist-stimulated cAMP accumulation. Blockade of intracellular Ca2+ mobilization abolished the substance K receptor-mediated inhibition of isoproterenol-induced cAMP production. Phosphodiesterase inhibitors, down-regulation or inhibition of protein kinase C, and pertussis toxin failed to prevent substance K-induced inhibition of agonist-stimulated cAMP accumulation. An increased intracellular Ca2+ concentration caused by either calcium ionophores or activation of endogenous bradykinin receptors was found to markedly reduce cAMP production in wild-type cells. These results demonstrate that elevated intracellular Ca2+ concentration can negatively modulate agonist-stimulated adenylate cyclase activity in C6-2B glioma cells.
DeBernardi
M A
MA
Department of Biochemistry and Molecular Biology, Georgetown University School of Medicine, Washington, DC 20007.
Seki
T
T
Brooker
G
G
D015056:1-Methyl-3-isobutylxanthine / Q000494:pharmacology; D012368:4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone / Q000494:pharmacology; D000262:Adenylyl Cyclases / Q000378:metabolism*; D000818:Animals; D001920:Bradykinin / Q000494:pharmacology; D000001:Calcimycin / Q000494:pharmacology; D002118:Calcium / Q000502:physiology*; D002417:Cattle; D002460:Cell Line; D002772:Cholera Toxin / Q000494:pharmacology; D000242:Cyclic AMP / Q000378:metabolism*; D004247:DNA / Q000235:genetics*; D005910:Glioma; D007545:Isoproterenol / Q000494:pharmacology*; D007700:Kinetics; D015288:Neurokinin A / Q000378:metabolism / Q000494:pharmacology*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D015398:Signal Transduction / Q000187:drug effects; D014162:Transfection
D012333:RNA, Messenger; D018041:Receptors, Neurokinin-2; D017981:Receptors, Neurotransmitter; D012368:4-(3-Butoxy-4-methoxybenzyl)-2-imidazolidinone; D000001:Calcimycin; D015288:Neurokinin A; D004247:DNA; D002772:Cholera Toxin; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D007545:Isoproterenol; D001920:Bradykinin; D002118:Calcium; D015056:1-Methyl-3-isobutylxanthine