Referenced in: none

Automatically associated channels: Kv10.1

Title: 7Li nuclear magnetic resonance study for the determination of Li+ properties in neuroblastoma SH-SY5Y cells.

Authors: J Nikolakopoulos, C Zachariah, D Mota de Freitas, E B Stubbs, R Ramasamy, M C Castro, C F Geraldes

Journal, date & volume: J. Neurochem., 1998 Oct , 71, 1676-84

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/9751202

Abstract
Lithium has been used clinically in the treatment of manic depression. However, its pharmacologic mode of action remains unclear. Characteristics of Li+ interactions in red blood cells (RBCs) have been identified. We investigated Li+ interactions on human neuroblastoma SH-SY5Y cells by developing a novel 7Li NMR method that provided a clear estimation of the intra- and extracellular amounts of Li+ in the presence of the shift reagent thulium-1,4,7,10-tetrazacyclododecane-N,N',N'',N'''-tetramethylene phosphonate (HTmDOTP4-). The first-order rate constants of Li+ influx and efflux for perfused, agarose-embedded SH-SY5Y cells in the presence of 3 mM HTmDOTP4- were 0.055 +/- 0.006 (n = 4) and -0.025 +/- 0.006 min(-1) (n = 3), respectively. Significant increases in the rate constants of Li+ influx and efflux in the presence of 0.05 mM veratridine indicated the presence of Na+ channel-mediated Li+ transport in SH-SY5Y cells. 7Li NMR relaxation measurements showed that Li+ is immobilized more in human neuroblastoma SH-SY5Y cells than in human RBCs.