Taylor I K, Wellings R, Taylor G W, Fuller R W
Department of Clinical Pharmacology, Royal Postgraduate Medical School, London, United Kingdom.
J Appl Physiol (1985). 1992 Aug;73(2):743-8. doi: 10.1152/jappl.1992.73.2.743.
Recent evidence suggests that the cysteinyl-leukotrienes (LTC4, LTD4, and LTE4) may be important in the pathogenesis of exercise-induced asthma. To evaluate the role of these mediators further, nine asthmatic subjects with exercise-induced bronchoconstriction were studied on two occasions. On visit 1, subjects performed 6 min of treadmill exercise; the mean maximal percent fall in FEV1 was 38.0 +/- 5.3%. On visit 2, maximal bronchoconstriction observed after exercise was matched with aerosolized methacholine. Urine was collected in two 90-min fractions (0-90 and 90-180 min) after challenges and analyzed by high-performance liquid chromatography-radioimmunoassay for LTE4. There were no significant differences in urinary LTE4 excretion between exercise and methacholine challenges for the periods 0-90 min (16.9 +/- 5.4 vs. 20.4 +/- 4.2 ng/mmol urinary creatinine), 90-180 min (24.9 +/- 8.2 vs. 20.1 +/- 5.5), or 0-180 min (21.5 +/- 6.5 vs. 18.8 +/- 4.1). Thus in contrast to allergen-induced bronchoconstriction, there is little evidence for enhanced cysteinyl-leukotriene generation in exercise-induced bronchoconstriction as assessed by urinary LTE4. If local release and subsequent participation of functionally active cysteinyl-leukotrienes in the pathways that ultimately lead to bronchoconstriction after exercise challenge do occur, these are of insufficient magnitude to perturb urinary LTE4 excretion.
近期证据表明，半胱氨酰白三烯（LTC4、LTD4和LTE4）可能在运动诱发哮喘的发病机制中起重要作用。为了进一步评估这些介质的作用，对9名运动诱发性支气管收缩的哮喘患者进行了两次研究。在第一次就诊时，受试者进行6分钟的跑步机运动；FEV1的平均最大下降百分比为38.0±5.3%。在第二次就诊时，将运动后观察到的最大支气管收缩与雾化乙酰甲胆碱相匹配。在激发后，以两个90分钟时间段（0 - 90分钟和90 - 180分钟）收集尿液，并通过高效液相色谱 - 放射免疫分析法分析LTE4。在0 - 90分钟时间段（尿肌酐中LTE4排泄量为16.9±5.4对20.4±4.2 ng/mmol）、90 - 180分钟时间段（24.9±8.2对20.1±5.5）或0 - 180分钟时间段（21.5±6.5对18.8±4.1），运动激发和乙酰甲胆碱激发后的尿LTE4排泄量无显著差异。因此，与变应原诱发的支气管收缩不同，通过尿LTE4评估，几乎没有证据表明运动诱发的支气管收缩中半胱氨酰白三烯生成增加。如果在运动激发后，具有功能活性的半胱氨酰白三烯确实在最终导致支气管收缩的途径中发生局部释放并随后参与其中，那么这些释放量不足以干扰尿LTE4排泄。
