Kioumis I, Lammers J W, Dent G, Chung K F, Barnes P J
Department of Thoracic Medicine, Brompton Hospital, London, U.K.
Prostaglandins. 1988 Sep;36(3):343-54. doi: 10.1016/0090-6980(88)90075-5.
We studied the effect of five successive inhalations of platelet-activating factor (PAF) on airway calibre, circulating neutrophil and platelet counts and the activation of these cells ex vivo in normal subjects. PAF (24 ug) caused a mean maximal fall of the expiratory flow rate at 70% vital capacity from a partial manoeuvre (Vp30) of 46.4 +/- 6.2% (p less than 0.001); there was a tachyphylactic response to further doses of PAF. Circulating neutrophil counts fell by 54.3 +/- 10.6% (p less than 0.005) with immediate recovery and with a rebound neutrophilia by the fifth inhalation. Platelet counts showed no significant changes. Aggregation of platelets in platelet-rich plasma to PAF and ADP in vitro at 15 min after the first, second and fifth PAF inhalations was not significantly altered. Chemiluminescence responses of neutrophils to PAF (0.01, 0.1, 1 and 10 microM) in vitro were reduced at 15 min after the fifth PAF inhalation, but this was only significant at 1 microM PAF. Methacholine inhalation did not cause any changes in responsiveness of neutrophils to PAF ex vivo. We conclude that ex vivo platelet desensitisation cannot be used as an index of endogenous PAF release, but reduced responsiveness of neutrophils ex vivo is not a sensitive indicator.
我们研究了在正常受试者中连续五次吸入血小板活化因子（PAF）对气道口径、循环中性粒细胞和血小板计数以及这些细胞体外活化的影响。PAF（24微克）通过部分操作（Vp30）使70%肺活量时的呼气流量率平均最大下降46.4±6.2%（p<0.001）；对进一步剂量的PAF出现快速减敏反应。循环中性粒细胞计数下降54.3±10.6%（p<0.005），随后立即恢复，到第五次吸入时出现中性粒细胞增多反弹。血小板计数无显著变化。在第一次、第二次和第五次吸入PAF后15分钟，富含血小板血浆中的血小板对PAF和ADP的体外聚集未显著改变。在第五次吸入PAF后15分钟，中性粒细胞对PAF（0.01、0.1、1和10微摩尔）的体外化学发光反应降低，但仅在1微摩尔PAF时具有统计学意义。吸入乙酰甲胆碱未引起中性粒细胞对PAF体外反应性的任何变化。我们得出结论，体外血小板脱敏不能用作内源性PAF释放的指标，但中性粒细胞体外反应性降低不是一个敏感指标。
