Inhibition of the inward-rectifying Cl- channel in rat choroid plexus by a decrease in extracellular pH.
AUTOR(ES)
Kajita, H
RESUMO
1. The sensitivity of the inward-rectifying Cl- channel in choroid plexus to changes in external pH (pHo) was examined. 2. Cl- currents were recorded using whole-cell patch-clamp methods. The inward-rectifying channel was activated by 375 nM of the catalytic subunit of protein kinase A which was added to the electrode solution. 3. Reducing pHo from 7.3 to 6.5 inhibited the inward-rectifying Cl- currents, whereas an increase in current was observed when pHo was elevated to 8.5. The inhibition of the conductance exhibited a sigmoidal relationship with decreasing pH over a range of 8.5 to 5.5. A half-maximal inhibition of the current was observed at pH 7.3. 4. The inhibition of the whole-cell current by reducing pHo suggests that it is carried by channels which are distinct from other inward-rectifier Cl- channels, e.g. ClC-2, phospholemman and the channel in Xenopus oocytes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1159186Documentos Relacionados
- K+-Selective Inward-Rectifying Channels and Apoplastic pH in Barley Roots1
- Physiological Roles of Inward-Rectifying K+ Channels.
- Inhibition of a small-conductance cAMP-dependent Cl- channel in the mouse thick ascending limb at low internal pH.
- A Novel Cl− Inward-Rectifying Current in the Plasma Membrane of the Calcifying Marine Phytoplankton Coccolithus pelagicus1
- Voltage-dependent inactivation of inward-rectifying single-channel currents in the guinea-pig heart cell membrane.
