The venom of scorpion B. martensi selectively inhibits transient outward K+ currents in neonatal rat ventricular cells and K(V)+ channel currents in NG108-15 cells

Abstract

In this communication, the effects of the venom and/or minimolecular component of Chinese scorpion Buthus martensi Karsch (BmK) on nine kinds of K+ or Cl- channels have been scanned under voltage- and patch-clamp recording conditions. The venom showed weak blockade to voltage-gated K+ channels in NG108-15 cells, while a reversible blocking effect of the minimolecular component on transient outward K+ currents was distinctly observed in neonatal rat ventricular cells. Among nine channels tested, little effect was observed on the other seven channels. The present results suggest that Chinese scorpion BmK contains a novel class of active minimolecule, which selectively binds to K+ channel family, in addition to the known polypeptides which bind to Na+ channels.