caa a22 4500 477074162 CHVBK 20180405111435.0 cr unu---uuuuu 170330e19960701xx s 000 0 eng 10.1007/BF02262780 doi (NATIONALLICENCE)springer-10.1007/BF02262780 Magura E. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, Ukraine aut Effects of (±)-kavain on inactivation of voltage-operated Na+ channels [Elektronische Daten] [E. Magura] Effects of a kava-pyrone (±)-kavain on fast inactivation of Na+ channels were studied in experiments on isolated neurons from the rat hippocampus. (±)-Kavain was found to block Na+ channels, and its effect was voltage-dependent. At the holding potentials of −100 and −80 mV, IC50 for (±)-kavain was 744.9 and 178.8 µM, respectively. The inactivation characteristic of Na+ channels was satisfactorily described with the Boltzmann's equation both in the control and under (±)-kavain application. (±)-Kavain at a 330 µM concentration shifted theV 1/2 toward more negative values by 14.4 mV and concurrently modified the slope factor: the latter was 5.7 mV in the control, while under the influence of 330 µM (±)-kavain it reached 6.7 mV. In agreement with Hille's hypothesis of a "modulated receptor,” inactivated Na+ channels demonstrated an increased sensitivity to kavain. (±)-Kavain effects resulted in an increase in the rate of depolarization-related fast inactivation, while the process of recovery from inactivation became slower when the membrane was hyperpolarized. Our data show that under the (±)-kavain effect the probability of the inactivated state of Na+ channels increases, and the state of fast inactivation is stabilized. Plenum Publishing Corporation, 1997 Neurophysiology Kluwer Academic Publishers-Plenum Publishers 28/4-5(1996-07-01), 173-177 0090-2977 28:4-5<173 1996 28 11062 https://doi.org/10.1007/BF02262780 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02262780 text/html Onlinezugriff via DOI NATIONALLICENCE 100 1- Magura E. Bogomolets Institute of Physiology, National Academy of Sciences of Ukraine, Kiev, Ukraine aut NATIONALLICENCE 773 0- Neurophysiology Kluwer Academic Publishers-Plenum Publishers 28/4-5(1996-07-01), 173-177 0090-2977 28:4-5<173 1996 28 11062 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer