Modulation of ionic currents in isolated type I cells of the neonatal rat carotid body by p-chloromercuribenzenesulfonic acid.
The sulphydryl reagent, p-chloromercuribenzenesulfonic acid (PCMBS), irreversibly excites the carotid body in vivo. We tested the effects of PCMBS on ionic currents in isolated type I cells, using the whole-cell patch-clamp technique. PCMBS selectively and irreversibly inhibited the Ca(2+)-activated K+ current (IKCa) in a dose-dependent manner (0.01-1 mM). The same concentrations of PCMBS did not affect the Ca(2+)-independent K+ current (IKv), but caused a transient enhancement of the Ca2+ current (ICa). The inhibition of IKCa by PCMBS is similar to the previously reported effects of hypoxia, and suggests a central role for the channels underlying this current in chemotransduction.
Wyatt
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Department of Pharmacology, Leeds University, UK.
Peers
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D002731:4-Chloromercuribenzenesulfonate / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn / Q000378:metabolism*; D015220:Calcium Channels / Q000187:drug effects*; D002344:Carotid Body / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D066298:In Vitro Techniques; D008564:Membrane Potentials / Q000187:drug effects; D015221:Potassium Channels / Q000187:drug effects*; D051381:Rats
D015220:Calcium Channels; D015221:Potassium Channels; D002731:4-Chloromercuribenzenesulfonate