Chilton F H, Murphy R C
Biochem Biophys Res Commun. 1987 Jun 30;145(3):1126-33. doi: 10.1016/0006-291x(87)91554-3.
Incorporation of arachidonic acid into phospholipid molecular species of the human neutrophil was found to be dependent, to a large extent, upon the concentration of arachidonate used during the in vitro incubations. When high concentrations of [3H] arachidonate were employed, only two glycerolipids incorporated label. One glycerolipid was a unique glycerophospholipid characterized by HPLC retention time and fast atom bombardment mass spectrometry as 1,2-diarachidonoyl-sn-glycero-3-phosphocholine. The second and most highly labeled glycerolipid was found to be arachidonoyl triacylglycerol species. Human neutrophils isolated from normal individuals and not previously exposed to arachidonic acid in vitro were found to contain a small but measurable amount of diarachidonoyl-GPC. The dose-dependent increase of diarachidonoyl-GPC and arachidonoyl-labeled triacylglycerol when cells were exposed to increasing concentrations of arachidonic acid implied that these lipid molecular species have the capacity to expand their pools, perhaps in manner regulating levels of endogenous arachidonic acid for further metabolism. These observations point to the importance of the concentration of arachidonic acid employed during in vitro labeling studies.
研究发现，花生四烯酸掺入人中性粒细胞磷脂分子种类的过程在很大程度上取决于体外孵育期间所用花生四烯酸盐的浓度。当使用高浓度的[3H]花生四烯酸盐时，只有两种甘油脂掺入了放射性标记。一种甘油脂是一种独特的甘油磷脂，通过高效液相色谱保留时间和快原子轰击质谱法鉴定为1,2 - 二花生四烯酰 - sn - 甘油 - 3 - 磷酸胆碱。第二种且标记程度最高的甘油脂被发现是花生四烯酰三酰甘油种类。从正常个体分离且此前未在体外接触过花生四烯酸的人中性粒细胞被发现含有少量但可测量的二花生四烯酰 - GPC。当细胞暴露于浓度不断增加的花生四烯酸时，二花生四烯酰 - GPC和花生四烯酰标记的三酰甘油呈剂量依赖性增加，这表明这些脂质分子种类有能力扩大其储备库，可能是以调节内源性花生四烯酸水平以进行进一步代谢的方式。这些观察结果表明了体外标记研究中所用花生四烯酸浓度的重要性。
