title: Dendrotoxin blocks a class of potassium channels that are opened by inhibitory presynaptic modulators in rat cortical synaptosomes and slices.
abstract: 1. Rat cortical synaptosomes were prelabeled with radioactive acetylcholine and the release induced by veratridine was determined in the absence and presence of the inhibitory presynaptic modulators, 2-chloroadenosine, carbamylcholine, clonidine, and morphine. All four agents inhibited the evoked release of acetylcholine and this inhibition was reversed by dendrotoxin. 2. Using perfused cortical slices and an extracellular K-sensitive electrode, all modulators again increased K efflux that was blocked by dendrotoxin. In contrast, glybenclamide and tetraethylammonium did not block the modulator-induced efflux.
authors.affiliation: Department of Pharmacology, Yale University School of Medicine, New Haven, Connecticut 06510.
authors.forename: G
authors.initials: G
authors.lastname: Zoltay
authors.forename: J R
authors.initials: JR
authors.lastname: Cooper
mesh_terms: D015762:2-Chloroadenosine / Q000494:pharmacology; D000109:Acetylcholine / Q000378:metabolism; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D002540:Cerebral Cortex / Q000187:drug effects*; D003000:Clonidine / Q000494:pharmacology; D004546:Elapid Venoms / Q000494:pharmacology*; D005905:Glyburide / Q000494:pharmacology; D015640:Ion Channel Gating / Q000187:drug effects*; D009020:Morphine / Q000494:pharmacology; D015221:Potassium Channels / Q000187:drug effects*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013574:Synaptosomes / Q000187:drug effects*; D019789:Tetraethylammonium; D013757:Tetraethylammonium Compounds / Q000494:pharmacology; D014701:Veratridine / Q000494:pharmacology
chemical_list: D004546:Elapid Venoms; D015221:Potassium Channels; D013757:Tetraethylammonium Compounds; D015762:2-Chloroadenosine; D019789:Tetraethylammonium; D014701:Veratridine; C020273:dendrotoxin; D009020:Morphine; D002217:Carbachol; D003000:Clonidine; D000109:Acetylcholine; D005905:Glyburide