Cellular and pharmacological studies for protection ofneuronal and endothelial cells

在本研究中，我们研究了神经细胞和内皮细胞功能的药理和生化机制。结果表明：1)在PC12细胞中，多巴胺能神经元的内源性神经毒素1，2，3，4-四氢异喹啉引起细胞迟发性死亡。2)S-亚硝基-半胱氨酸是一种稳定的内源性NO化合物，被L类氨基酸转运蛋白掺入PC12细胞中。S亚硝基半胱氨酸对PC12细胞胞浆磷脂酶A2和钙通道等功能蛋白的亚硝化作用可能是通过S亚硝化介导的。S-亚硝基-半胱氨酸的作用可被L-亮氨酸等特定氨基酸所抑制。3)分泌型磷脂酶A2在神经细胞中表达，其活性受氧化苯基砷等SH基活性物质的调节。膜分泌型磷脂酶A2的活性可能受…的调节更多的是膜相关和氧化还原水平的调节蛋白，如蛋白质二硫键异构酶。4)抑制超氧化物歧化酶使PC12细胞花生四烯酸释放增加，胞浆磷脂酶A2的mRNA和蛋白水平升高。几种神经酰胺类似物和1-磷酸鱼腥草素类似物调节神经细胞中花生四烯酸的代谢。5)中枢注射辣椒素和花青胺激活香草素受体1和痛肽激活阿片受体样1(ORL1)受体，通过迷走神经机制引起胃酸分泌。中枢神经系统中的kappa-阿片受体系统与中枢神经系统中的谷氨酸和γ-氨基丁酸受体系统的激活，从而刺激大鼠胃酸的分泌。6)中乌头碱等乌头类生物碱可激活大鼠主动脉内钙内流和一氧化氮合酶，从而引起大鼠主动脉松弛。在大鼠小动脉，中乌头碱引起的钙内流通过产生内皮源性超极化因子而起到松弛作用。米特拉宁相关的吲哚生物碱具有阿片激动剂活性，其中7位羟基对阿片受体的激活具有重要作用。较少

We investigated the pharmacological and biochemical mechanisms of neuronal and endothelial cells functions in the present study. The results were : 1) In PC12 cells, 1,2,3,4-tetrahydroisoquinoline, an endogenous neurotoxin for dopaminergic neurons, caused the delayed cell death. The mRNAs of IL6 and cytosolic phospholipase A2 levels in PCI2 cells were regulated by TIQ treatment 2) S-Nitroso-cysteine, a stable and endogenous NO compound, is incorporated by the L-type amino acid transporter in PC 12 cells. The effects of S-nitroso-cysteine appeared to be mediated by S-nitrosylation of functional proteins such as cytosolic phospholipase A2 and Ca2+-channels in PC 12 cells. The effects of S-nitroso-cysteine were inhibited by specific amino acids such as L-leucine. 3) Secretory type of phospholipase A2 is expressed in neuronal cells, and the activity was regulated by the SH group-reactive agents such as phenylarsine oxide. The activity of secretory phospholipase A2 in membrane may be regula … More ted by the membrane-associated and redox-level regulating proteins such as protein disulfide isomerase. 4) Inhibition of superoxise dismutase caused an increase of arachidonic acid release and mRNA and protein levels of cytosolic phospholipase A2 in PC12 cells. Several ceramide analogs and sphyngosine-1-phosphate analogs regulated arachidonic acid metabolism in neuronal cells. 5) Activation of vanilloid receptor 1 by the central injection of capsaicin and anandamide and the activation of opioid receptor-like 1 (ORL1) receptor by nociceptin caused gastric acid secretion through mechanisms involving the vagus nerve in rats. Activation of kappa-opioid receptor system in the CNS coupled with glutamate and gamma-amino butyric acid receptor systems in the CNS, and thus stimulated gastric acid secretion in rats. 6) Aconite alkaloids such as mesaconitine showed activation of Ca2+ influx and NO synthase and thus caused relaxation in rat aorta. In rat small artery, Ca2+ influx induced by mesaconitine caused relaxation via the production of endothelium-derived hyperpolarizing factor. Mitragynine-related indole alkaloids showed the opioid agonistic activities, and the OH-group in the 7-position was important for the activation of opioid receptors. Less