Effects of D600 on hypoxic suppression of K+ currents in isolated type I carotid body cells of the neonatal rat.
K+ currents recorded from isolated type I carotid body cells were reversibly suppressed by hypoxia (pO2 25 Torr). Inhibition of Ca2+ influx using high Mg2+, low Ca2+ solutions abolished this effect, indicating hypoxia selectively inhibits the Ca2(+)-activated component of K+ currents. The Ca2+ channel blockers D600 and verapamil reversed the suppressive effects of hypoxia. These drugs also partially inhibited Ca2(+)-independent K+ currents, but this effect was relieved by hypoxia, causing apparent reversal of hypoxic suppression of the K+ currents seen under control conditions.
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University Laboratory of Physiology, Oxford, UK.
D000818:Animals; D000831:Animals, Newborn; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000187:drug effects*; D002344:Carotid Body / Q000187:drug effects / Q000378:metabolism*; D002478:Cells, Cultured; D005711:Gallopamil / Q000494:pharmacology*; D008274:Magnesium / Q000378:metabolism; D010100:Oxygen / Q000494:pharmacology*; D011188:Potassium / Q000378:metabolism; D015221:Potassium Channels / Q000187:drug effects*; D051381:Rats; D014700:Verapamil / Q000494:pharmacology
D015220:Calcium Channels; D015221:Potassium Channels; D005711:Gallopamil; D014700:Verapamil; D008274:Magnesium; D011188:Potassium; D010100:Oxygen; D002118:Calcium