Kurokawa K, Tanaka H, Tanaka S, Abe S
Third Department of Internal Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan.
Chest. 2001 Dec;120(6):1822-8. doi: 10.1378/chest.120.6.1822.
Circadian rhythmicity of cysteinyl leukotrienes (LTs) and thromboxane (TX)-A(2) in healthy subjects and nocturnal asthmatic patients remains a subject of controversy. The aim of this study was to investigate the contribution of these mediators to the pathogenesis of nocturnal asthma.
We measured peak expiratory flow rate, urinary concentration of LTE(4), 11-dehydro-TXB(2), and creatinine eight times every 3 h in three groups: healthy control subjects (n = 5, group A), nocturnal asthmatic patients (n = 9, group B), and nonnocturnal asthmatic subjects (n = 9, group C). To evaluate the reproducibility of the measurement of urinary LTE(4), we measured urinary LTE(4) in group A for 3 separate days.
The urinary LTE(4) concentrations from 3 to 6 AM were significantly (p < 0.05) higher than from 3 to 6 PM in both group A and group B, but not in group C. The mean levels of LTE(4) in group B and group C were significantly higher (p < 0.05) than those in group A. In group B, another small peak was observed from 6 to 9 PM. No significant day-to-day variation was observed in group A. Urinary 11-dehydro-TXB(2) values from 3 to 6 AM were significantly (p < 0.001) higher than those levels from 3 to 6 PM in all groups, and the mean levels in group B and group C were significantly higher than those in group A (p < 0.05).
Circadian rhythmicity of urinary LTE(4) with a morning peak was found in healthy control subjects and nocturnal asthmatic subjects, but not in nonnocturnal asthmatic patients. It was suggested that cysteinyl LTs rather than TXA(2) might contribute to the nocturnal worsening of asthma.
健康受试者和夜间哮喘患者中半胱氨酰白三烯（LTs）和血栓素（TX）-A2的昼夜节律性仍是一个有争议的话题。本研究的目的是调查这些介质在夜间哮喘发病机制中的作用。
我们在三组中每3小时测量一次呼气峰值流速、尿LTE4、11-脱氢-TXB2和肌酐浓度，共测量8次：健康对照受试者（n = 5，A组）、夜间哮喘患者（n = 9，B组）和非夜间哮喘受试者（n = 9，C组）。为了评估尿LTE4测量的可重复性，我们在A组中连续3天测量尿LTE4。
A组和B组中，凌晨3点至6点的尿LTE4浓度显著高于下午3点至6点（p < 0.05），但C组并非如此。B组和C组的LTE4平均水平显著高于A组（p < 0.05）。在B组中，下午6点至9点观察到另一个小峰值。A组未观察到显著的日间变化。所有组中，凌晨3点至6点的尿11-脱氢-TXB2值显著高于下午3点至6点的水平（p < 0.001），B组和C组的平均水平显著高于A组（p < 0.05）。
在健康对照受试者和夜间哮喘受试者中发现了尿LTE4的昼夜节律性且早晨出现峰值，但在非夜间哮喘患者中未发现。提示半胱氨酰白三烯而非血栓素A2可能导致哮喘的夜间加重。
