R56865 as Ca2+-channel blocker in Purkinje neurons of rat: Comparison with flunarizine and nimodipine

摘要: Abstract The blocking action of recently synthesized benzothiazolamine derivative R56865 was compared with that dihydropyridine (nimodipine) and diphenylalkylamine (flunarizine) on low-voltage-activated non-inactivating high-voltage-activated Ca 2+ currents. experiments were carried out freshly isolated Purkinje neurons rat cerebellum using patch-clamp technique in the whole-cell configuration. Among substances tested found to be most effective blocker current. In sequence R56865, flunarizine nimodipine, apparent K d values for current are 0.1, 0.9 3.5 μM, 3.1, 9.5 38 respectively. current-voltage relationships both types currents displayed little or no shift under either but showed a 10-mV positive direction nimodipine. steady-state inactivation curves calcium shifted nimodipine (in concentrations which blocked 50–60% current) more negative membrane potentials 20, 10 6 mV, contrast channel use-dependent manner. It is concluded order potency antagonist channels studied > Strong relationship by can further facilitate its vivo conditions.