Metabolic fate of platelet-activating factor in the rat enterocyte: the role of a specific lysophospholipase D.
Metabolic fate of platelet-activating factor in the rat enterocyte: the role of a specific lysophospholipase D.
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大鼠肠上皮细胞中血小板激活因子的代谢命运：特定溶血磷脂酶 D 的作用。
DOI：
10.1006/abbi.1995.1292
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Johnston,JM
中科院分区：
文献类型：
--
作者：
Furukawa,M;Muguruma,K;Frenkel,RA;Johnston,JM
本文用1-[~ 3 H]十八烷基-2-乙酰基-sn-甘油-3-磷酸胆碱研究了血小板活化因子（PAF）在离体大鼠肠上皮细胞中的代谢。由细胞产生的主要代谢产物是1-O-烷基甘油，发现其与细胞和培养基相关。当使用肠上皮细胞系（INT 407）进行类似研究时，PAF几乎定量转化为1-烷基-2-酰基-sn-甘油-3-磷酸胆碱（AAGPC）。当肠上皮细胞微粒体在氟化物的存在下孵育以抑制磷酸水解酶活性时，1-烷基甘油的形成减少，与1-烷基甘油磷酸的化学计量增加相关，表明肠细胞中存在溶血磷脂酶D。当磷脂酶D的活性进行了检查，在微粒体部分制备肠上皮细胞，溶血PAF是首选的基板和只有痕量的溶血PAF转化为烷基酰基-GPC。酰基异-GPC快速裂解形成游离脂肪酸。INT 407细胞中不存在溶血磷脂酶D活性不能归因于这些细胞中不存在刷状缘，因为在分离的刷状缘制备物中不存在溶血磷脂酶D活性。
The metabolism of platelet-activating factor (PAF) by isolated rat intestinal epithelial cells was investigated using 1-[3H]octadecyl-2-acetyl-sn-glycero-3-phosphocholine. The principal metabolite produced by the cells was 1-O-alkylglycerol, which was found in association with the cells and the medium. When similar studies were conducted employing an intestinal epithelial cell line (INT 407), PAF was almost quantitatively converted into 1-alkyl-2-acyl-sn-glycero-3-phosphocholine (AAGPC). When the intestinal epithelial cell microsomes were incubated in the presence of fluoride to inhibit phosphohydrolase activity, the formation of 1-alkylglycerol was decreased in association with a stoichiometric increase in 1-alkylglycerophosphate, indicating the presence of a lysophospholipase D in the intestinal cells. When the phospholipase D activity was examined in the microsomal fraction prepared from intestinal epithelial cells, lyso-PAF was the preferred substrate and only trace amounts of lyso-PAF were converted into alkylacyl-GPC. Acyllyso-GPC was rapidly cleaved to form free fatty acids. The absence of lysophospholipase D activity in INT 407 cells cannot be attributed to the absence of brush border in these cells since no lysophospholipase D activity was present in isolated brush border preparations.