O'Donnell M C, Henson P M, Fiedel B A
Immunology. 1978 Dec;35(6):953-8.
Rabbit basophil-derived platelet activating factor (PAF), a mediator of anaphylaxis, induces the aggregation and release of serotonin from rabbit platelets. In the present study, we report that PAF obtained by challenge of specifically sensitized rabbit basophils induced the noncytotoxic release of serotonin from human platelets; maximal extent of release ranged between 34-46%. This release was unaltered in the presence of indomethacin, indicating that such secretion was not a consequence of contaminating arachidonic acid; further, as previously demonstrated with platelets of rabbit origin, it was markedly independent of a requirement for an intact prostaglandin biosynthetic pathway. In contrast to its effect upon rabbit platelets, rabbit PAF did not induce aggregation of human platelets, suggesting that the aggregation and secretion reactions induced by this agent are separable and that this cross-species activation may be incomplete. Whether this is a result of the differential ability of rabbit PAF to bind to and activate rabbit as compared to human platelets or to the existence of a family of PAF molecules is not yet known. The capacity of PAF to participate in a secretory event involving human platelets lends support to the belief that PAF may play an important ubiquitous role in the cooperative, leucocyte-dependent, release of vasoactive amines which results in increased vascular permeability.
兔嗜碱性粒细胞衍生的血小板激活因子（PAF）是一种过敏反应介质，可诱导兔血小板中5-羟色胺的聚集和释放。在本研究中，我们报告，通过刺激特异性致敏的兔嗜碱性粒细胞获得的PAF可诱导人血小板非细胞毒性释放5-羟色胺；最大释放程度在34%-46%之间。在吲哚美辛存在的情况下，这种释放未发生改变，表明这种分泌不是花生四烯酸污染的结果；此外，如先前对兔源血小板的研究所证明的，它明显独立于完整前列腺素生物合成途径的需求。与对兔血小板的作用相反，兔PAF不诱导人血小板聚集，这表明该介质诱导的聚集和分泌反应是可分离的，并且这种跨物种激活可能是不完全的。这是由于兔PAF与人血小板相比，与兔血小板结合并激活的能力不同，还是由于存在PAF分子家族，目前尚不清楚。PAF参与涉及人血小板的分泌事件的能力支持了这样一种观点，即PAF可能在导致血管通透性增加的血管活性胺的协同、白细胞依赖性释放中发挥重要的普遍作用。
