NOOTROPIC DRUG VINPOCETINE BLOCKS POTASSI UM CHANNELS MORE EFFICIENTLY THAN CALCIUM CHANNELS

In isolated neurons of Helix snail high-threshold Ca2+-and K+-currents were recorded using two-microelectrode voltage clamp technique. Extra cellular application of nootropic drug vinpocetine rapidly and reversi bly blocked both types of current. Vinpocetine effects were dose-depen dent and voltage-independent. The maximal effect of Ca2+-current block ade was 27% during application of vinpocetine in the concentration of 600 mcM. The maximal blockade of K+-current was 75% when the drug was applied in the concentration of 30 mcM. Results suggest that K+-channe ls are more probable targets for vinpocetine than Ca2+-channels.