Shukla S D, Hanahan D J
Arch Biochem Biophys. 1984 Aug 1;232(2):458-66. doi: 10.1016/0003-9861(84)90562-9.
When 32Pi-labeled rabbit platelets were incubated with 5 X 10(-10) M 1-O-alkyl-2-acetyl-sn-glyceryl-3-phosphorylcholine (AGEPC), either in the presence or absence (0.1 mM EGTA) of added Ca2+, there was a three- to five-fold increase in the [32P]phosphatidic acid (PA) pool within 15 to 20 s. This event was followed by a gradual decrease in the [32P]PA level to near basal level in 5 min. AGEPC effected this change in [32P]PA in a characteristic dose- and time-dependent manner. Polar head group analogs of AGEPC, such as AGEDME and AGEMME, also effected an increase in PA labeling at levels comparable to those previously reported for their activity toward rabbit platelets [K. Satouchi, R. N. Pinckard, L. M., McManus, and D. J. Hanahan (1981) J. Biol. Chem. 256, 4425-4432]. Other analogs, i.e., lysoGEPC and the enantiomer, sn-1-AGEPC, which are inactive toward rabbit platelets, also showed no effect on the level of [32P]PA. The finding that the PA level in rabbit platelets could be manipulated by the addition of AGEPC, without any added Ca2+, provided an excellent model system for establishing a correlation between the uptake of Ca2+, serotonin release, and PA level. Thus, PA must be regarded as a sensitive indicator of a reaction mechanism important to the platelet response to AGEPC, and could be the focal point in promoting calcium uptake during the stimulation process.
当用5×10⁻¹⁰ M的1-O-烷基-2-乙酰基-sn-甘油-3-磷酸胆碱（AGEPC）孵育³²P标记的兔血小板时，无论是否添加Ca²⁺（0.1 mM EGTA），在15至20秒内，[³²P]磷脂酸（PA）池增加了三到五倍。此事件之后，[³²P]PA水平在5分钟内逐渐降至接近基础水平。AGEPC以特征性的剂量和时间依赖性方式影响[³²P]PA的这种变化。AGEPC的极性头部类似物，如AGEDME和AGEMME，也使PA标记增加，其水平与先前报道的它们对兔血小板的活性相当[K. Satouchi, R. N. Pinckard, L. M., McManus, and D. J. Hanahan (1981) J. Biol. Chem. 256, 4425 - 4432]。其他类似物，即对兔血小板无活性的溶血甘油磷酰胆碱和对映体sn-1-AGEPC，对[³²P]PA水平也无影响。在不添加任何Ca²⁺的情况下，通过添加AGEPC可以操纵兔血小板中的PA水平，这一发现为建立Ca²⁺摄取、血清素释放和PA水平之间的相关性提供了一个出色的模型系统。因此，PA必须被视为对血小板对AGEPC反应很重要的反应机制的敏感指标，并且可能是刺激过程中促进钙摄取的焦点。
