Pharmacology of the Ca2+‐dependent K+ channel in corn protoplasts
- 12 November 1990
- journal article
- Published by Wiley in FEBS Letters
- Vol. 274 (1-2) , 115-118
- https://doi.org/10.1016/0014-5793(90)81343-m
Abstract
We investigated the sensitivity of the Ca2+-dependent K+ current, IK(Ca), present in corn protoplasts, to different K+ channel blockers. IK(Ca) was inhibited by external Cs+ (10 mM), Ba2+ (10 mM), and quinine (0.5 mM): reagents which block many types of outward-rectifying K+ channels. In contrast 4-aminopyridine (5 mM), an inhibitor of delayed rectifier or inactivating K+ currents, had no effect. Neither of the peptide toxins, apamin or charybdotoxin, specific for Ca2+-dependent K+ channels in animal cells, inhibited currents when used in the nanomolar concentration range. However, higher levels of charybdotoxin (10 μM) caused marked reduction of IK(Ca)Keywords
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