(+)-Tubocurarine is a potent inhibitor of cation channels in the vacuolar membrane of Chenopodium rubrum L.
The effect of the acetylcholine antagonist and channel blocker (+)-tubocurarine on the calcium-dependent slow vacuolar (SV) cation channels in the tonoplast of suspension-cultured cells of Chenopodium rubrum L. was examined using the patch-clamp technique. In whole-vacuolar recordings the drug strongly suppressed the potassium conductance (EC50: 6 microM) and altered the kinetics of channel inactivation. In excised membrane patches (+)-tubocurarine evokes channel-'flickering' without affecting the single-channel conductance (approx. 80 pS).
Botanisches Institut I der Justus-Liebig-Universität, Giessen, Germany.
T
T
Weiser
F W
FW
Bentrup
D002412:Cations; D002474:Cell-Free System; D004553:Electric Conductivity / Q000187:drug effects; D066298:In Vitro Techniques; D007425:Intracellular Membranes / Q000502:physiology; D007473:Ion Channels / Q000187:drug effects*; D010944:Plants; D014403:Tubocurarine / Q000494:pharmacology*; D014617:Vacuoles / Q000187:drug effects*
D002412:Cations; D007473:Ion Channels; D014403:Tubocurarine