Intracellular alkalinization enhances inward rectifier K+ current in retinal horizontal cells of catfish.
Isolated cone-driven horizontal cells dissociated from catfish retina were voltage-clamped using the whole-cell patch-clamp technique. The effects of acidification and alkalinization on an anomalous type, inwardly-rectifying K+ current (IRK+) were investigated. The magnitude of IRK+ was enhanced by raising the intracellular pH above 7.4, however, in contrast, intracellular acidification had little effect on this current. The range over which intracellular pH ([pH]i) modulates IRK+ is different from that for modulation of a sustained high-voltage activated calcium current in these same cells and also for proton-sensitive, inward rectifier currents in starfish oocytes, skeletal muscle and heart myocytes.
Takahashi
K
K
Department of Physiology, Keio University School of Medicine, Tokyo, Japan.
Copenhagen
D R
DR
D000818:Animals; D006863:Hydrogen-Ion Concentration; D007059:Ictaluridae / Q000502:physiology*; D066298:In Vitro Techniques; D015221:Potassium Channels / Q000502:physiology*; D024661:Potassium Channels, Inwardly Rectifying; D012160:Retina / Q000166:cytology / Q000502:physiology*
D015221:Potassium Channels; D024661:Potassium Channels, Inwardly Rectifying