[Lipoxygenase inhibitors, eicosapolynoic acids, attenuate the short-term plasticity of the cholinoreceptors of snail neurons].

On identified Helix neurones RPa3 and LPa3 with the use of the double-electrode voltage clamp technique on the membrane the influence was studied of three polyacetilenic analogues of natural polyenoic acids which were the inhibitors of their lipoxygenase oxidation on the dynamics of inward current extinction, caused by the repeated iontophoretic applications of acetylcholine to soma. It was found that 5, 8, 11, 14-eicosatetraynoic acid (30-60 microM) and 5, 8, 11, 14, 17-eicosapentaynoic acid (4-5 microM) decreased the amplitude of inward current caused by acetylcholine leading and weakened its extinction at the repeated applications. The third analogue -8, 11, 14-eicosatrynoic acid had no modulating influence on the value of current and on its extinction. The supposition was made that lipoxygenase metabolites of polyenoic acids regulated plasticity of Helix neurones cholinoreceptors. Considering different inhibiting by the used compounds of various lipoxygenases the most probable was participation in regulation of cholinoreceptors plasticity of those eicosanoids which were formed from arachidonic acid under the influence of 5-lipoxygenase. Regulating role of eicosanoids formed at the action of other lipoxygenases was not excluded.