Redox modulation of A-type K+ currents in pain-sensing dorsal root ganglion neurons.
Redox modulation of fast inactivation has been described in certain cloned A-type voltage-gated K(+) (Kv) channels in expressing systems, but the effects remain to be demonstrated in native neurons. In this study, we examined the effects of cysteine-specific redox agents on the A-type K(+) currents in acutely dissociated small diameter dorsal root ganglion (DRG) neurons from rats. The fast inactivation of most A-type currents was markedly removed or slowed by the oxidizing agents 2,2'-dithio-bis(5-nitropyridine) (DTBNP) and chloramine-T. Dithiothreitol, a reducing agent for the disulfide bond, restored the inactivation. These results demonstrated that native A-type K(+) channels, probably Kv1.4, could switch the roles between inactivating and non-inactivating K(+) channels via redox regulation in pain-sensing DRG neurons. The A-type channels may play a role in adjusting pain sensitivity in response to peripheral redox conditions.
Hsieh
Chi-Pan
CP
Department of Physiology, College of Medicine, National Taiwan University, No. 1, Jen-Ai Road, 1st Section, Taipei 100, Taiwan. hsiehcp@ntu.edu.tw
D000818:Animals; D002700:Chloramines / Q000494:pharmacology*; D003545:Cysteine / Q000187:drug effects; D004229:Dithiothreitol / Q000494:pharmacology; D005727:Ganglia, Spinal / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051605:Kv Channel-Interacting Proteins / Q000187:drug effects* / Q000378:metabolism; D051665:Kv1.4 Potassium Channel / Q000187:drug effects / Q000378:metabolism; D009475:Neurons, Afferent / Q000187:drug effects* / Q000378:metabolism; D016877:Oxidants / Q000494:pharmacology*; D010084:Oxidation-Reduction; D010146:Pain / Q000503:physiopathology*; D011725:Pyridines / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar; D014105:Tosyl Compounds / Q000494:pharmacology*
D002700:Chloramines; D051605:Kv Channel-Interacting Proteins; D051665:Kv1.4 Potassium Channel; D016877:Oxidants; D011725:Pyridines; D014105:Tosyl Compounds; C016300:chloramine-T; C011801:2,2'-dithiobis(5-nitropyridine); D003545:Cysteine; D004229:Dithiothreitol