Calcium current characterization in dissociated adult guinea-pig jugular ganglion neurons.
Voltage-dependent calcium (Ca2+) channel currents in freshly dissociated adult guinea-pig jugular ganglion neurons were examined and characterized using the whole-cell patch-clamp technique. Electrophysiological analysis demonstrated a high-threshold current, but no low-threshold or T-type current. A fraction of the total Ca2+ current was inhibited by omega (omega)-conotoxin GVIA (Cg (inTX; 10 microM); the dihydropyridine antagonist nifedipine (NIF; 10 microM), inhibited a large fraction of the CgTX-insensitive current. The remaining CgTX/NIF-insensitive current was completely inhibited by omega-agatoxin IVA (AgIVA; 100 nM). These results demonstrated that the whole-cell Ca2+ channel current consisted only of N-, L- P-type components. Of these currents, only the L-type was partially inhibited by both histamine and carbachol (0.01-100 microM).
Danks
P
P
Department of Pharmacology, Zeneca Pharmaceuticals Group, Zeneca Inc., Wilmington, DE 19897.
Spence
K T
KT
Togo
J A
JA
Christian
E P
EP
ffrench-Mullen
J M
JM
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000378:metabolism*; D004594:Electrophysiology; D005726:Ganglia, Parasympathetic / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D009475:Neurons, Afferent / Q000187:drug effects / Q000378:metabolism*; D010277:Parasympathomimetics / Q000494:pharmacology
D002121:Calcium Channel Blockers; D015220:Calcium Channels; D010277:Parasympathomimetics; D006632:Histamine