Bradykinin inhibition of N- and L-type calcium channel currents in NG108-15 cells.
The bradykinin regulation of calcium channel currents in NG108-15 neuroblastoma x glioma hybrid cells was examined, in order to determine: (1) which type of bradykinin receptors mediates the inhibition of N-type calcium channels in these cells; and (2) whether bradykinin can modulate other types of calcium channels in these cells. Bradykinin inhibited both N- and L-type calcium channels in NG108-15 cells, with EC50S of 10 +/- 2 nM and 29 +/- 7 nM, respectively. The inhibition of both L- and N-type calcium channels by bradykinin (100 nM) could be completely inhibited by the bradykinin B2 receptor antagonist Hoe 140 (10 nM). Bradykinin appeared to inhibit that portion of the L-type calcium channel current that was also reversibly inhibited by omega-conotoxin GVIA. The bradykinin inhibition of the L-type calcium channel current was partly reduced by pretreatment of the cells with pertussis toxin, whereas the inhibition of the N-type current was pertussis toxin-insensitive. In some cultures it was observed that the bradykinin B1 receptor agonist desArg9bradykinin inhibited the L-type calcium channel current.
Connor
M
M
Department of Pharmacology, University of Bristol, UK.
Henderson
G
G
D001920:Bradykinin / Q000494:pharmacology*; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D006822:Hybrid Cells / Q000187:drug effects; D018408:Patch-Clamp Techniques; D010455:Peptides / Q000494:pharmacology; D037342:Pertussis Toxin; D014407:Tumor Cells, Cultured; D010566:Virulence Factors, Bordetella / Q000494:pharmacology; D020866:omega-Conotoxin GVIA
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D010455:Peptides; D010566:Virulence Factors, Bordetella; D020866:omega-Conotoxin GVIA; D037342:Pertussis Toxin; D001920:Bradykinin