Smolen J E, Shohet S B
J Clin Invest. 1974 Mar;53(3):726-34. doi: 10.1172/JCI107611.
During phagocytosis, new phospholipid is synthesized from triglyceride fatty acid and may be utilized to form the membranes of phagocytic vesicles. In addition, hydrogen peroxide, which can peroxidize unsaturated fatty acids, is generated. Since both of these processes could change membrane fatty acid composition during the conversion of cytoplasmic granules and plasma membranes to phagosomes, the lipid compositions of these structures were examined. Phagocytic vesicles were prepared by density gradient centrifugation of polystyrene latex particles after phagocytosis. Granule and plasma membrane fractions were isolated by density gradient and differential centrifugation. Phospholipids and fatty acids were analyzed by thin-layer chromatography and gas-liquid chromatography. While whole cells, granules, plasma membranes, and phagosomes were all similar in phospholipid composition, phagosome fatty acids were significantly more saturated than those of the other fractions. This was primarily due to reduced oleic and arachidonic acids and increased palmitic acid in the phagocytic vesicle lipids. Plasma membrane was also more saturated in comparison to whole cells and granules. However, this difference was not sufficient to explain the marked comparative saturation of the phagosomes. The observed increase in fatty acid saturation in these lipids may have been induced by a combination of either peroxidative destruction of polyunsaturated fatty acids or phospholipase activity, coupled with reacylation mechanisms favoring saturated fatty acids.
在吞噬作用过程中，新的磷脂由甘油三酯脂肪酸合成，并可用于形成吞噬小泡的膜。此外，还会产生能使不饱和脂肪酸过氧化的过氧化氢。由于在细胞质颗粒和质膜转化为吞噬体的过程中，这两个过程都可能改变膜脂肪酸组成，因此对这些结构的脂质组成进行了检测。吞噬作用发生后，通过对聚苯乙烯乳胶颗粒进行密度梯度离心来制备吞噬小泡。通过密度梯度离心和差速离心分离颗粒和质膜部分。通过薄层色谱法和气液色谱法分析磷脂和脂肪酸。虽然全细胞、颗粒、质膜和吞噬体在磷脂组成上都相似，但吞噬体脂肪酸的饱和度明显高于其他部分。这主要是由于吞噬小泡脂质中油酸和花生四烯酸减少，棕榈酸增加。与全细胞和颗粒相比，质膜的饱和度也更高。然而，这种差异不足以解释吞噬体明显更高的饱和度。这些脂质中观察到的脂肪酸饱和度增加可能是由多不饱和脂肪酸的过氧化破坏或磷脂酶活性，再加上有利于饱和脂肪酸的再酰化机制共同诱导的。
