Single K+ channels closed by light and opened by cyclic GMP in molluscan extra-ocular photoreceptor cells.
We report the first recordings of the light-sensitive channel which is active during dark and is closed by light in the Onchidium extra-ocular photoreceptor cells. This light-sensitive channel was K-selective and was not blocked by extracellular Ca2+ and Mg2+. Application of cyclic GMP to excised inside-out patches activated (opened) a channel that appeared to be the same as the light-sensitive channel recorded from the same membrane in the intact cell.
Department of Physiology, Faculty of Medicine, Kagoshima University, Japan.
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Gotow
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Nishi
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Kijima
D000818:Animals; D002118:Calcium / Q000494:pharmacology; D006152:Cyclic GMP / Q000494:pharmacology*; D004594:Electrophysiology; D017952:Ganglia, Invertebrate / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008027:Light; D008274:Magnesium / Q000494:pharmacology; D008974:Mollusca / Q000502:physiology*; D017956:Photoreceptor Cells, Invertebrate / Q000187:drug effects* / Q000378:metabolism / Q000528:radiation effects*; D015221:Potassium Channels / Q000187:drug effects* / Q000528:radiation effects*
D015221:Potassium Channels; D006152:Cyclic GMP; D008274:Magnesium; D002118:Calcium