[The effect of a decrease in the mobilization of Ca+ and its chemo-controlled intake into the cytoplasm on the...

The effects of extracellular solution without Ca2+ and inhibitors of Ca2+ mobilization dependent of Ca2+ (tetracaine) and inositol-1,4,5-trisphosphate (TMB-8) on the modulation of cholinoreceptor (ChR) plasticity of identified Helix lucorum RPa3 and LPa3 neurons by 15(S)-hydroxy-(5Z,8Z,11Z,13E)-eicosatetraenoic acid (15-HETE) were investigated. Using the double-electrode voltage-clamp technique, the inward current, induced by local ionophoretic acetylcholine application (ACh-current), was recorded. ChR plasticity was evaluated by extinction of ACh-current developed in a process of rhythmic ACh applications on the soma with an interval 60-240 s. Tetracaine and TMB-8 disturbed long-latent modulatory effect of 15-HETE and did not influence short-latent one. Extraction of Ca2+ from extracellular solution did not affect the modulatory effect of 15-HETE. It was concluded that one of the molecular mechanisms of ChR plasticity deepening due 15-HETE (in long-latent phase) induces potentiation of Ca(2+)- and inositol-1,4,5-trisphosphate-dependent Ca2+ mobilization evoked by 5-lipoxygenase eicosanoids.