title: Kavain inhibits non-stereospecifically veratridine-activated Na+ channels.
abstract: The action of the natural kava pyrone, (+)-kavain, and its synthetic racemate, (+/-)-kavain, on voltage-dependent Na+ channels was investigated, while considering their stereospecific properties, on veratridine-induced increases in cytosolic free Na+ and Ca2+ ([Na+]i, [Ca2+]i) and the release of endogenous glutamate from cerebrocortical synaptosomes. Both compounds dose-dependently suppressed the veratridine-induced increase in [Na+]i, [Ca2+]i and glutamate release with IC50 values (+/- S.D.) of 71 +/- 22, 72 +/- 7, 120 +/- 37 micromol/l (+)-kavain and 77 +/- 21, 90 +/- 14, 92 +/- 23 micromol/l (+/-)-kavain, respectively. As judged from the dose-dependency, IC50 values, velocity and time course of action, both kava pyrones were equally effective suggesting a non-stereospecific inhibition of veratridine-activated Na+ channels.
authors.affiliation: University Clinics Ulm, Institute of Naturheilkunde, Helmholtzstr. 20, D-89081 Ulm, Germany.
authors.forename: J
authors.initials: J
authors.lastname: Gleitz
authors.forename: N
authors.initials: N
authors.lastname: Gottner
authors.forename: A
authors.initials: A
authors.lastname: Ameri
authors.forename: T
authors.initials: T
authors.lastname: Peters