INVOLVEMENT OF K-INDUCED INHIBITION OF NEUROBLASTOMA CELL-GROWTH( CHANNELS IN THE QUERCETIN)

The effects of the flavonoid quercetin on cell proliferation and volta ge-dependent K+ current were studied on mouse neuroblastoma X glioma h ybrid cells. In the presence of 1 % fetal calf serum, quercetin inhibi ted both cell proliferation and K+ current with effective doses induci ng half-maximum effects of 10 muM and 70 muM respectively. Valinomycin (1 nM) antagonized 80 % of the growth-inhibitory effects of 10 muM qu ercetin. The results suggest that at least a part of the antiprolifera tive effect of quercetin is mediated by a K+ channel blockade. They fu rther confirm a role for K+ channels in mitogenesis and cell prolifera tion.