Referenced in: none

Automatically associated channels: Kir6.2 , Slo1

Title: Inhibition of sodium channels in rat dorsal root ganglion neurons by Hainantoxin-IV, a novel spider toxin.

Authors: Yu-Cheng Xiao, Song-Ping Liang

Journal, date & volume: Sheng Wu Hua Xue Yu Sheng Wu Wu Li Xue Bao, 2003 Jan , 35, 82-5

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/12518233

Abstract
The effects of Hainantoxin-IV (HNTX-IV), a neurotoxic peptide isolated from the venom of the Chinese bird spider Seleconosmia hainana, on the adult rat dorsal root ganglion (DRG) neurons were investigated. Using the whole-cell patch-clamp technique HNTX-IV inhibited mammal neural TTX-sensitive (TTX-S) sodium currents evidently but the toxin failed to affect TTX-resistant (TTX-R) ones. The inhibition of HNTX-IV is dose-dependent with the IC(50) value of 44.6 nmol/L. The toxin didn't affect the activation and inactivation kinetics of sodium currents, but it caused a 10.1 mV hyperpolarizing shift in the voltage midpoint of steady-state sodium channel inactivation on DRG neurons. The results indicated that HNTX-IV, a novel spider toxin, maybe alternate voltage-gated sodium channels through a mechanism distinct from other spider toxins such as delta-ACTXs, mu-agatoxins I-VI which targeted the receptor site 3 to slow the inactivation kinetics of sodium currents.