Referenced in: none

Automatically associated channels: Nav1.8 , Nav1.9

Title: Effects of (-)-gallocatechin-3-gallate on tetrodotoxin-resistant voltage-gated sodium channels in rat dorsal root ganglion neurons.

Authors: Yan Zhang, Yan-Yan Jia, Jin-Lei Guo, Pei-qing Liu, Jian-Min Jiang

Journal, date & volume: Int J Mol Sci, 2013 , 14, 9779-89

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/23652835

Abstract
The (-)-gallocatechin-3-gallate (GCG) concentration in some tea beverages can account for as much as 50% of the total catechins. It has been shown that catechins have analgesic properties. Voltage-gated sodium channels (Nav) mediate neuronal action potentials. Tetrodotoxin inhibits all Nav isoforms, but Nav1.8 and Nav1.9 are relatively tetrodotoxin-resistant compared to other isoforms and functionally linked to nociception. In this study, the effects of GCG on tetrodotoxin-resistant Na+ currents were investigated in rat primary cultures of dorsal root ganglion neurons via the whole-cell patch-clamp technique. We found that 1 μM GCG reduced the amplitudes of peak current density of tetrodotoxin-resistant Na+ currents significantly. Furthermore, the inhibition was accompanied by a depolarizing shift of the activation voltage and a hyperpolarizing shift of steady-state inactivation voltage. The percentage block of GCG (1 μM) on tetrodotoxin-resistant Na+ current was 45.1% ± 1.1% in 10 min. In addition, GCG did not produce frequency-dependent block of tetrodotoxin-resistant Na+ currents at stimulation frequencies of 1 Hz, 2 Hz and 5 Hz. On the basis of these findings, we propose that GCG may be a potential analgesic agent.