Beauvericin-induced channels in ventricular myocytes and liposomes.
The antibiotic Beauvericin (BEA) was previously shown to express ionophoric properties under simple experimental systems. Its channel-forming activity was examined in inside-out patches of ventricular myocytes and synthetic membranes with the patch clamp and fluorescence imaging techniques. Current transitions to several open state levels were evident after wash-in. The BEA channel is cation-selective. Conductance and kinetics are presented for K(+) and Na(+) substates and main states. The pore was blocked by La(3+). In myocytes, the [K(+)](i) was reduced, while [Na(+)](i) and [Ca(2+)](i) increased, leading to cytolysis. These results indicate that BEA forms cation-selective channels in lipid membranes, which can affect the ionic homeostasis.
Kouri
K
K
Institute of Pharmacology and Toxicology, University of Vienna, Althanstrasse 14, 1090 Vienna, Austria. katerina.kouri@univie.ac.at
Lemmens
M
M
Lemmens-Gruber
R
R
D000818:Animals; D000900:Anti-Bacterial Agents / Q000037:antagonists & inhibitors / Q000378:metabolism / Q000494:pharmacology*; D015220:Calcium Channels / Q000378:metabolism; D002463:Cell Membrane Permeability; D002478:Cells, Cultured; D047630:Depsipeptides; D004553:Electric Conductivity; D005456:Fluorescent Dyes; D016257:Fura-2; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D006352:Heart Ventricles; D007476:Ionophores / Q000494:pharmacology*; D008081:Liposomes / Q000737:chemistry / Q000378:metabolism*; D009206:Myocardium / Q000737:chemistry / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D010455:Peptides; D015221:Potassium Channels / Q000378:metabolism; D015222:Sodium Channels / Q000378:metabolism
D000900:Anti-Bacterial Agents; D015220:Calcium Channels; D047630:Depsipeptides; D005456:Fluorescent Dyes; D007476:Ionophores; D008081:Liposomes; D010455:Peptides; D015221:Potassium Channels; D015222:Sodium Channels; C004456:beauvericin; D016257:Fura-2