Smal M A, Baldo B A
Kolling Institute of Medical Research, Royal North Shore Hospital, St. Leonards, N.S.W., Australia.
Lipids. 1991 Dec;26(12):1144-7. doi: 10.1007/BF02536519.
Quantitation of platelet-activating factor (PAF) in human saliva samples by radioimmunoassay indicated there was, at times, sufficient PAF present to aggregate platelets. However, in certain samples, we observed little or no aggregation, and furthermore, these samples were found to inhibit aggregation induced by PAF (200 pg). Chromatographic fractionation of pooled saliva increased the PAF activity 4-fold, and the observed inhibitory activity was found to co-migrate with the fatty acids. The inhibitory fraction was found to be active against platelet aggregation induced by arachidonic acid (3.4 nmole) as well as PAF (25 pg), but not thrombin (20 mU). These results indicate the existence of a PAF inhibitor in saliva, which may explain why potentially toxic levels of PAF can occur in the saliva of normal, healthy individuals. These findings also highlight an important advantage of the radioimmunoassay over platelet aggregation for the quantitation of PAF in, at least, some biological fluids.
通过放射免疫测定法定量检测人唾液样本中的血小板活化因子（PAF），结果表明，有时唾液中存在足以使血小板聚集的PAF。然而，在某些样本中，我们观察到很少或没有聚集现象，此外，还发现这些样本能抑制PAF（200 pg）诱导的聚集。对混合唾液进行色谱分离后，PAF活性增加了4倍，且观察到的抑制活性与脂肪酸共同迁移。发现抑制组分对花生四烯酸（3.4纳摩尔）和PAF（25 pg）诱导的血小板聚集均有活性，但对凝血酶（20 mU）诱导的血小板聚集无活性。这些结果表明唾液中存在PAF抑制剂，这可能解释了为何在正常健康个体的唾液中会出现潜在毒性水平的PAF。这些发现还突出了放射免疫测定法相对于血小板聚集法在至少某些生物体液中定量PAF方面的一个重要优势。
