Enhancement of low-threshold A-current of the neuronal membrane by vinpocetine.
A low-threshold fast inactivating K+ current (I(Alth)) was recorded in isolated land snail neurons using the two-microelectrode voltage clamp method. A nootropic drug, vinpocetine, applied to the extracellular medium at a concentration of 1-100 microM potentiated I(Alth). The potentiation consisted in a rise of its peak amplitude and an increase of the half-decay time. Vinpocetine did not cause a shift of the steady-state activation and inactivation curves along the potential axis. Dibutyryl cyclic GMP (dcGMP) also increased the peak amplitude but did not change the time of current half-decay. dcAMP did not potentiate I(Alth). The possible role of K+-current potentiation in neuronal membranes in therapy of dementia is discussed.
Solntseva
E I
EI
Institute of Brain Research, Russian Academy of Medical Sciences, Moscow.
Bukanova
J V
JV
D000818:Animals; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D002462:Cell Membrane / Q000502:physiology*; D004594:Electrophysiology; D017136:Ion Transport / Q000187:drug effects / Q000502:physiology; D008564:Membrane Potentials / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D011188:Potassium / Q000502:physiology*; D012908:Snails; D014748:Vinca Alkaloids / Q000494:pharmacology*
D002121:Calcium Channel Blockers; D014748:Vinca Alkaloids; C013983:vinpocetine; D011188:Potassium