Snyder Eric M, Olson Thomas P, Johnson Bruce D, Frantz Robert P
Department of Pharmacy Practice and Science, University of Arizona, 1703 E. Mabel, Tucson, AZ 85721, USA.
Eur J Appl Physiol. 2008 Jul;103(4):421-30. doi: 10.1007/s00421-008-0735-5.
We sought to determine the influence of sildenafil on the diffusing capacity of the lungs for carbon monoxide (DLCO) and the components of DLCO (pulmonary capillary blood volume VC, and alveolar-capillary membrane conductance DM) at rest and following exercise with normoxia and hypoxia. This double-blind placebo-controlled, cross-over study included 14 healthy subjects (age = 33 +/- 11 years, ht = 181 +/- 8 cm, weight = 85 +/- 14 kg, BMI = 26 +/- 3 kg/m2, peak normoxic VO2 = 36 +/- 6 ml/kg, mean +/- SD). Subjects were randomized to placebo or 100 mg sildenafil 1 h prior to entering a hypoxic tent with an FiO2 of 12.5% for 90 min. DLCO, VC, and DM were assessed at rest, every 3 min during exercise, at peak exercise, and 10 and 30 min post exercise. Sildenafil attenuated the elevation in PAP at rest and during recovery with exposure to hypoxia, but pulmonary arterial pressure immediately post exercise was not different between sildenafil and placebo. Systemic 02 saturation and VO2peak did not differ between the two conditions. DLCO was not different between groups at any time point. VC was higher with exercise in the placebo group, and the difference in DM between sildenafil and placebo was significant only when corrected for changes in VC (DM/VC = 0.57 +/- 0.29 vs. 0.41 +/- 0.16, P = 0.04). These results suggest no effect of sildenafil on DLCO, but an improvement in DM when corrected for changes in VC during short-term hypoxic exposure with exercise.
我们试图确定西地那非对静息状态以及常氧和低氧运动后肺一氧化碳弥散量（DLCO）及其组成部分（肺毛细血管血容量VC和肺泡-毛细血管膜传导率DM）的影响。这项双盲、安慰剂对照的交叉研究纳入了14名健康受试者（年龄=33±11岁，身高=181±8厘米，体重=85±14千克，体重指数=26±3千克/平方米，常氧峰值摄氧量=36±6毫升/千克，均值±标准差）。受试者在进入FiO₂为12.5%的低氧帐篷90分钟前1小时被随机分为安慰剂组或服用100毫克西地那非组。在静息状态、运动期间每3分钟、运动峰值以及运动后10分钟和30分钟评估DLCO、VC和DM。西地那非减轻了静息状态下以及低氧暴露恢复期间肺动脉压的升高，但运动后即刻西地那非组和安慰剂组的肺动脉压并无差异。两种情况下全身氧饱和度和峰值摄氧量没有差异。在任何时间点，两组之间的DLCO均无差异。安慰剂组运动时VC较高，仅在对VC变化进行校正后，西地那非组和安慰剂组之间的DM差异才有统计学意义（DM/VC = 0.57±0.29 vs. 0.41±0.16，P = 0.04）。这些结果表明西地那非对DLCO无影响，但在运动导致短期低氧暴露期间，校正VC变化后DM有所改善。
