Rustenbeck I, Lenzen S
Institute of Pharmacology, University of Göttingen, Federal Republic of Germany.
Naunyn Schmiedebergs Arch Pharmacol. 1989 Jan-Feb;339(1-2):37-41. doi: 10.1007/BF00165123.
The role of lysophosphatidylcholine and arachidonic acid in signal transduction was investigated using subcellular organelles and permeabilized cells from liver. Both substances can be generated intracellularly by the action of phospholipase A2 on phosphatidylcholine. Lysophosphatidylcholine as well as arachidonic acid raised the free Ca2+ concentration in the incubation media of permeabilized cells, isolated mitochondria and microsomes. The half maximally effective concentrations for Ca2+ release from mitochondria were 78 +/- 1 mumol/l for lysophosphatidylcholine and 80 +/- 11 mumol/l for arachidonic acid. Though isolated microsomes released Ca2+ in response to both agents, the combined presence of mitochondria and microsomes did not exhibit a synergism in Ca2+ release in response to arachidonic acid; the increase in the free Ca2+ concentration in response to lysophosphatidylcholine was even smaller than with mitochondria alone. It is concluded that the two reaction products of phospholipase A2 can raise the cytoplasmic Ca2+ concentration and therefore may participate in cellular signal transduction.
利用亚细胞器和来自肝脏的透化细胞，研究了溶血磷脂酰胆碱和花生四烯酸在信号转导中的作用。这两种物质都可通过磷脂酶A2作用于磷脂酰胆碱在细胞内生成。溶血磷脂酰胆碱以及花生四烯酸均可提高透化细胞、分离的线粒体和微粒体孵育介质中的游离钙离子浓度。线粒体释放钙离子的半数最大效应浓度，溶血磷脂酰胆碱为78±1μmol/L，花生四烯酸为80±11μmol/L。尽管分离的微粒体对这两种试剂均有反应释放钙离子，但线粒体和微粒体同时存在时，对花生四烯酸的钙离子释放未表现出协同作用；对溶血磷脂酰胆碱的游离钙离子浓度升高甚至比单独线粒体时更小。结论是磷脂酶A2的这两种反应产物可提高细胞质钙离子浓度，因此可能参与细胞信号转导。
