Temporal association of nitric oxide levels and airflow in asthma after whole lung allergen challenge
Temporal association of nitric oxide levels and airflow in asthma after whole lung allergen challenge
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DOI：
10.1152/japplphysiol.01127.2002
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发表时间：
2003-07-01
影响因子：
3.3
通讯作者：
Dweik, RA
中科院分区：
文献类型：
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作者：
Khatri, SB;Hammel, J;Dweik, RA
哮喘患者呼出的一氧化氮（NO）水平较高，并随病情加重而增加。我们假设，在哮喘急性发作过程中观察到的NO水平较高是由于NO合成增加。呼出的NO和峰值流量测定在11个哮喘和9个健康对照组受试者之前和之后的实验性哮喘反应诱导的全肺过敏原挑战。哮喘患者的基线峰值流量显著低于对照组，并且在激发后立即显著降低（P = 0.004）。通过收集不屏气的呼出气（诺奥）和屏气15秒后的呼出气（NO15）来测量NO。通过Δ NO/Δ t =（NO15 -诺奥）/ 15计算NO随时间的累积速率[ppm/十亿/秒（ppb/s）]，其中Δ表示变化，t是时间。哮喘和对照受试者的NO蓄积率在基线时相似;然而，与对照受试者相比，哮喘受试者24小时的NO蓄积较基线增加了3倍（哮喘受试者，0.6 +/- 0.2 ppb/s;对照受试者，0.2 +/- 0.1 ppb/s; P = 0.01）。我们的研究表明，在哮喘急性发作期间增加的NO是由于合成增加，可能是通过增加NO脱氢酶的表达。
Exhaled nitric oxide ( NO) levels are high in asthmatic subjects and increase with exacerbations. We hypothesized that higher levels of NO observed during asthma exacerbations are due to increased synthesis of NO. Exhaled NO and peak flows were measured in 11 asthmatic and 9 healthy control subjects before and after experimental asthmatic response induced by whole lung allergen challenge. Baseline peak flows of asthmatics were significantly lower than controls and decreased significantly immediately after challenge ( P = 0.004). NO was measured by collecting exhaled breaths without breath hold (NOo) and after a 15-s breath hold (NO15). The rate of NO accumulation over time [parts/ billion per second (ppb/s)] was calculated by DeltaNO/Deltat = (NO15 - NOo)/ 15, where Delta denotes a change and t is time. The NO accumulation rates in asthmatic and control subjects were similar at baseline; however, NO accumulation at 24 h increased threefold from baseline in asthmatic compared with control subjects ( asthmatic subjects, 0.6 +/- 0.2 ppb/s; control subjects, 0.2 +/- 0.1 ppb/s; P = 0.01). Our study suggests that increased NO during an asthma exacerbation is due to increased synthesis, perhaps by increased expression of NO synthases.