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.