Bradykinin-induced ion currents in cultured rat trigeminal ganglion cells.
Effects of bradykinin (BK) on membrane currents of cultured rat trigeminal ganglion cells were studied with a G omega-sealed discontinuous voltage clamp technique. Bradykinin (0.05 nM-1 microM) produced membrane depolarization in most cells and hyperpolarization in some cells via a variety of ionic mechanisms: (1) activation of a cation current, (2) enhancement or (3) inhibition of a hyperpolarization-activated inwardly rectifying cation current known as IH, (4) reduction or (5) enhancement of an outwardly rectifying outward current (presumably a delayed K+ current), (6) inhibition of a slow-gating voltage-dependent steady-state outward current (at > -55 mV) and/or (7) increase in another slow-gating voltage-dependent outward current (at > or = -70 mV). These components of BK-induced currents appeared in different combinations and extents among cells, explaining complex excitatory and modulatory actions of BK in different regions and types of sensory neurons.
Department of Physiology, Saga Medical School, Japan.
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Kitakoga
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Kuba
D000818:Animals; D001920:Bradykinin / Q000494:pharmacology*; D002412:Cations / Q000378:metabolism*; D002478:Cells, Cultured; D004553:Electric Conductivity; D006706:Homeostasis; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D012668:Trigeminal Ganglion / Q000166:cytology / Q000502:physiology*
D002412:Cations; D001920:Bradykinin