Takamura H, Narita H, Park H J, Tanaka K, Matsuura T, Kito M
J Biol Chem. 1987 Feb 15;262(5):2262-9.
Mass changes in the various molecular species of phospholipids were determined after stimulation of human platelets with thrombin and collagen. Upon stimulation, every molecular species of phosphatidylinositol and phosphatidylserine was equally hydrolyzed, whereas the molecular species of phosphatidylcholine and diacyl- and alkenylacylphosphatidylethanolamine containing arachidonic acid were selectively hydrolyzed. At low Ca2+ concentrations, which result from mobilization of intracellular Ca2+ stores, phosphatidylinositol, phosphatidylcholine, and diacylphosphatidylethanolamine were hydrolyzed after stimulation with thrombin, whereas only phosphatidylinositol was hydrolyzed with production of thromboxane B2 after stimulation with collagen. At high Ca2+ concentrations, phosphatidylcholine and diacylphosphatidylethanolamine were hydrolyzed after stimulation with collagen, and phosphatidylserine and alkenylacylphosphatidylethanolamine were degraded after stimulation with both thrombin and collagen. [1-14C]Arachidonic acid was heterogeneously incorporated into the individual molecular species of the various phospholipid classes, indicating that the determination of mass is essential for an accurate picture of phospholipid hydrolysis. The data reported here indicate that the Ca2+ concentration affects the differential degradation of phospholipid molecular species in activated human platelets.
在用凝血酶和胶原蛋白刺激人血小板后，测定了磷脂各种分子种类的质量变化。受到刺激后，磷脂酰肌醇和磷脂酰丝氨酸的每一种分子种类均被等量水解，而含有花生四烯酸的磷脂酰胆碱以及二酰基和烯基酰基磷脂酰乙醇胺的分子种类则被选择性水解。在因细胞内钙库动员导致的低钙离子浓度下，在用凝血酶刺激后，磷脂酰肌醇、磷脂酰胆碱和二酰基磷脂酰乙醇胺被水解，而在用胶原蛋白刺激后，只有磷脂酰肌醇被水解并产生血栓素B2。在高钙离子浓度下，在用胶原蛋白刺激后，磷脂酰胆碱和二酰基磷脂酰乙醇胺被水解，在用凝血酶和胶原蛋白刺激后，磷脂酰丝氨酸和烯基酰基磷脂酰乙醇胺被降解。[1-14C]花生四烯酸以异质性方式掺入各种磷脂类别的各个分子种类中，这表明质量测定对于准确了解磷脂水解情况至关重要。此处报道的数据表明，钙离子浓度会影响活化的人血小板中磷脂分子种类的差异降解。
