Diamant S, Avraham B, Atlas D
FEBS Lett. 1987 Jul 27;219(2):445-50. doi: 10.1016/0014-5793(87)80269-7.
The possible involvement of phosphoinositides' turnover in the process of neurotransmitter release in the central nervous system (CNS) was studied using rat brain slices and synaptosomes. A depolarizing concentration of potassium chloride (25 mM) induces an 8.6 +/- 0.4% increase of [3H]noradrenaline [( 3H]NA) fractional release in cerebral cortical slices above spontaneous release, and 15 mM KCl induces a 3-fold increase of [3H]NA release in rat brain synaptosomes. Neomycin, an aminoglycoside which binds phosphoinositides, inhibits the potassium-induced release in cortical slices with an IC50 = 0.5 +/- 0.07 mM and with IC50 = 0.2 +/- 0.03 mM in synaptosomes. Veratridine, a veratrum alkaloid which increases membrane permeability to sodium ions and causes depolarization of neuronal cells, induces a net 13.4 +/- 0.3% increase of [3H]NA fractional release above spontaneous release in cortical slices. In analogy to K+ stimulation, neomycin inhibits the veratridine-stimulated release in cortical slices with an IC50 = 0.65 +/- 0.1 mM. It appears that the recycling of phosphoinositides, which is necessary for Ca2+ mobilization, participates in the Ca2+-dependent induced neurotransmitter release in the central nervous system.
利用大鼠脑片和突触体研究了磷酸肌醇代谢周转在中枢神经系统（CNS）神经递质释放过程中的可能作用。去极化浓度的氯化钾（25 mM）可使大脑皮层切片中[3H]去甲肾上腺素（[3H]NA）的分数释放比自发释放增加8.6±0.4%，而15 mM KCl可使大鼠脑突触体中[3H]NA的释放增加3倍。新霉素是一种能结合磷酸肌醇的氨基糖苷类药物，在皮层切片中抑制钾诱导的释放，IC50 = 0.5±0.07 mM，在突触体中的IC50 = 0.2±0.03 mM。藜芦碱是一种藜芦生物碱，可增加细胞膜对钠离子的通透性并导致神经元细胞去极化，可使皮层切片中[3H]NA的分数释放比自发释放净增加13.4±0.3%。与钾刺激类似，新霉素在皮层切片中抑制藜芦碱刺激的释放，IC50 = 0.65±0.1 mM。似乎对钙离子动员所必需的磷酸肌醇再循环参与了中枢神经系统中依赖钙离子诱导的神经递质释放。
