Bupivacaine blocks N-type inactivating Kv channels in the open state: no allosteric effect on inactivation kinetics.

ABSTRACT: Local anesthetics bind to ion channels in a state-dependent manner. For noninactivating voltage-gated K channels the binding mainly occurs in the open state, while for voltage-gated inactivating Na channels it is assumed to occur mainly in inactivated states, leading to an allosterically caused increase in the inactivation probability, reflected in a negative shift of the steady-state inactivation curve, prolonged recovery from inactivation, and a frequency-dependent block. How local anesthetics bind to N-type inactivating K channels is less explored. In this study, we have compared bupivacaine effects on inactivating (Shaker and K(v)3.4) and noninactivating (Shaker-IR and K(v)3.2) channels, expressed in Xenopus oocytes. Bupivacaine was found to block these channels time-dependently withou

SUBMITTER: Nilsson J 

PROVIDER: S-EPMC2586568 | biostudies-literature | 2008 Dec

REPOSITORIES: biostudies-literature