[Effect of batrachotoxin on the selectivity of sodium channels in the membrane of a myelinated nerve fiber].
Ionic currents under voltage clamp conditions were studied in the Ranvier node treated with batrachotoxin (5-10(-6)--10(-5) M). Ionic permeability ratios were measured from zero-current potential. The permeability sequence for modified (noninactivating) Na channels was: Tl greater than NH4 greater than Na approximately Li greater than K greater than guanidinum greater than Rb greater than Ca greater than Cs greater than methylamine. Deviation from the "independence relation" in modified channels for It1 was decreased.
D000818:Animals; D001001:Anura; D001496:Batrachotoxins / Q000494:pharmacology*; D002463:Cell Membrane Permeability / Q000187:drug effects*; D011898:Ranidae; D011901:Ranvier's Nodes / Q000187:drug effects* / Q000378:metabolism; D012964:Sodium / Q000378:metabolism*
D001496:Batrachotoxins; D012964:Sodium
Vliianie batrakhotoksina na selektivnost' natrievykh kanalov v membrane mielinizirovannogo nervnogo volokna.