Mechanism of inhibition by hydrogen sulfide of native and recombinant BKCa channels
| Autor: | Paul J. Kemp, S. Cayzac, Daniela Riccardi, Vsevolod Telezhkin, William J. Wilkinson, Stephen P. Brazier |
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| Rok vydání: | 2010 |
| Předmět: |
Male
Pulmonary and Respiratory Medicine BK channel Patch-Clamp Techniques Physiology Cystathionine beta-Synthase Transfection Cell Line law.invention Glomus cell law Potassium Channel Blockers medicine Animals Humans Hydrogen Sulfide Large-Conductance Calcium-Activated Potassium Channels RNA Messenger Patch clamp Rats Wistar Potassium Cyanide Air Pollutants Carotid Body biology Reverse Transcriptase Polymerase Chain Reaction Chemistry General Neuroscience Cystathionine gamma-Lyase Potassium channel blocker Anatomy Immunohistochemistry Recombinant Proteins Potassium channel Rats Electrophysiology medicine.anatomical_structure Cell culture Mutation Recombinant DNA biology.protein Biophysics Carotid body medicine.drug |
| Zdroj: | Respiratory Physiology & Neurobiology. 172:169-178 |
| ISSN: | 1569-9048 |
| DOI: | 10.1016/j.resp.2010.05.016 |
| Popis: | Recent evidence suggests that H(2)S contributes to activation of the carotid body by hypoxia by inhibiting K(+) channels. Here, we determine both the molecular identity of the K(+) channel target within the carotid body and the biophysical characteristics of the H(2)S-evoked inhibition by analyzing native rat and human recombinant BK(Ca) channel activity in voltage-clamped, inside-out membrane patches. Rat glomus cells express the enzymes necessary for the endogenous generation of H(2)S, cystathionine-beta-synthase and cystathionine-gamma-lyase. H(2)S inhibits native carotid body and human recombinant BK(Ca) channels with IC(50) values of around 275 microM. Inhibition by H(2)S is rapid and reversible, works by a mechanism which is distinct from that suggested for CO gas regulation of this channel and does not involve an interaction with either the "Ca bowl" or residues distal to this Ca(2+)-sensing domain. These data show that BK(Ca) is a K(+) channel target of H(2)S, and suggest a mechanism to explain the H(2)S-dependent component of O(2) sensing in the carotid body. |
| Databáze: | OpenAIRE |
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