ENHANCEMENT OF THE SHAKER-B-DELTA-6-46 CURRENT BY FATTY-ACIDS DEPENDSON THE ACTIVATION OF THE LIPOXYGENASE METABOLIC PATHWAY

Voltage-gated K+ channels are modulated by extracellular free unsatura ted fatty acids. Both increases and attenuations of K+ channel activit ies have been observed. We studied the effect of cis-unsaturated fatty acids on Shaker B Delta 6-46 and the endogenous outward rectifier Kchannels expressed in COS cell line, using the whole cell recording te chnique. For both K+ channels, exogenously applied unsaturated fatty a cids dramatically increased the outward K+ currents. This enhancement was not mediated by cylooxygenase or epoxygenase (P450) enzymes. Howev er, nordihydroguaiaretic acid, a lipoxygenase metabolic pathway blocke r, did prevent the arachidonic acid-induced Shaker current enhancement .