Modulation of platelet-activating factor (PAF) synthesis and release from human polymorphonuclear leukocytes (PMN): role of extracellular albumin.
Modulation of platelet-activating factor (PAF) synthesis and release from human polymorphonuclear leukocytes (PMN): role of extracellular albumin.
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调节人多形核白细胞（PMN）的血小板激活因子（PAF）合成和释放：细胞外白蛋白的作用。
DOI：
10.1016/0003-9861(85)90555-7
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发表时间：
1985
影响因子：
3.9
通讯作者：
Pinckard,RN
中科院分区：
文献类型：
--
作者：
Ludwig,JC;Hoppens,CL;McManus,LM;Mott,GE;Pinckard,RN
人中性粒细胞经N‘-甲酰-甲硫基-亮氨酰-苯丙氨酸刺激后，在细胞松弛素B的存在下，仅合成少量的血小板活化因子，刺激后在60-120 S范围内达到最高水平，且不释放血小板活化因子。当HSA浓度为2.5 mg/ml时，PAF合成增加3倍，其中30-40%在FMLP刺激后5分钟内释放。在50 mg HSA/ml存在下，PAF的合成和释放至少增加4倍，最大合成出现在刺激后10-20分钟。因此，在PMN刺激过程中，HSA的存在不仅诱导白蛋白剂量依赖性地增加PAF的释放，而且显著增加PAF的合成。与PAF的合成和释放相反，人血清白蛋白对FMLP刺激的中性粒细胞溶酶体酶分泌没有影响，在刺激后30-60 S达到最大值。这些结果表明，HSA在人PMN合成和释放PAF的体外过程中起重要作用，并支持在刺激的人PMN中存在循环的PAF合成-释放偶联机制的假说。
Human neutrophilic polymorphonuclear leukocytes (PMN) stimulated withN′-formyl-methionyl-leucyl-phenylalanine (FMLP) in the presence of cytochalasin B but in the absence of human serum albumin (HSA) synthesized only small amounts of platelet-activating factor (PAF) that attained maximum levels within 60–120 s after stimulation; in addition, no release of PAF occurred. However, in the presence of 2.5 mg HSA/ml, there was a threefold increase in PAF synthesis, 30–40% of which was released within 5 min after FMLP stimulation. In the presence of 50 mg HSA/ml there was at least a fourfold increase in PAF synthesis and release, with maximal synthesis occurring 10–20 min after stimulation. Thus, the presence of HSA during PMN stimulation not only induced an albumin dose-dependent increase in PAF release but significantly augmented the synthesis of PAF. In contrast to PAF synthesis and release, the presence or absence of HSA had no effect upon lysosomal enzyme secretion from FMLP-stimulated PMN, which was maximal within 30–60 s after stimulation. These results demonstrate that HSA plays an essential rolein vitroin the synthesis and release of PAF from human PMN, and support the hypothesis that there is a cyclic PAF synthesis-release coupling mechanism in the stimulated human PMN.