Bradykinin evoked depolarization of a novel neuroblastoma x DRG neurone hybrid cell line (ND7/23).
Application of bradykinin (Bk) to neuroblastoma x dorsal root ganglion (DRG) neurone hybrid cells (ND7/23) evoked an inward (depolarizing) current associated with an increase in membrane conductance. This response was antagonized by D-Arg0,Hyp3,Thi5,8,D-Phe7-Bk, but was not mimicked by des-Arg9-Bk, indicating the involvement of B2-receptors. The response was unaltered by replacement of extracellular Na+ by N-methylglucamine. Replacement of extracellular Cl by gluconate shifted the estimate reversal potential to a more positive value, while the use of potassium acetate filled recording electrodes shifted the reversal potential to a more negative value, and reduced the response amplitude, indicating the importance of Cl- in the response. This response to Bk was mimicked by the calcium ionophore ionomycin. Bk stimulated the formation of inositol 1,4,5-trisphosphate (IP3), and increased the release of arachidonic acid. In addition, Bk produced an increase in [Ca2+]i, as determined by microspectrofluorimetry. This was due to the release of Ca2+ from intracellular stores, since the response was unaltered when the cells were bathed in Ca(2+)-free solution. In summary, Bk depolarizes ND7/23 cells, probably through the activation of a chloride conductance. It seems likely that this is secondary to the rise in cytosolic Ca2+ concentration, due to the release of Ca2+ from internal stores by IP3. This Ca(2+)-activated chloride response is present in some sensory neurones, although its role in the activation of sensory neurones by Bk is at present unclear.
Dunn
P M
PM
Sandoz Institute for Medical Research, London, U.K.
Coote
P R
PR
Wood
J N
JN
Burgess
G M
GM
Rang
H P
HP
D000470:Alkaloids / Q000494:pharmacology; D000818:Animals; D016718:Arachidonic Acid; D001095:Arachidonic Acids / Q000378:metabolism; D001920:Bradykinin / Q000494:pharmacology*; D002118:Calcium / Q000378:metabolism; D002462:Cell Membrane / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D005071:Evoked Potentials / Q000187:drug effects; D005727:Ganglia, Spinal / Q000502:physiology; D006822:Hybrid Cells / Q000187:drug effects / Q000502:physiology*; D007295:Inositol Phosphates / Q000378:metabolism; D015759:Ionomycin / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D009447:Neuroblastoma; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D015240:Phorbol 12,13-Dibutyrate / Q000494:pharmacology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D051381:Rats; D018002:Receptors, Bradykinin; D017981:Receptors, Neurotransmitter / Q000187:drug effects / Q000502:physiology; D015290:Second Messenger Systems / Q000187:drug effects; D019311:Staurosporine
D000470:Alkaloids; D001095:Arachidonic Acids; D007295:Inositol Phosphates; D018002:Receptors, Bradykinin; D017981:Receptors, Neurotransmitter; D016718:Arachidonic Acid; D015240:Phorbol 12,13-Dibutyrate; D015759:Ionomycin; D011493:Protein Kinase C; D019311:Staurosporine; D001920:Bradykinin; D002118:Calcium