Mohsenin V
John B. Pierce Foundation Laboratory, Yale University, New Haven, CT 06519.
Am Rev Respir Dis. 1987 Dec;136(6):1408-11. doi: 10.1164/ajrccm/136.6.1408.
We conducted a double-blind randomized study to determine the effect of vitamin C on NO2-induced airway hyperresponsiveness in normal subjects. Eleven normal subjects were randomly assigned an order for 4 experimental exposures. For each exposure, subjects took either vitamin C (500 mg 4 times a day for 3 days) or placebo followed by exposure either to clean air or to 2.0 ppm NO2. Measurements of lung mechanics and airway responsiveness to methacholine aerosol were obtained. Serum level of ascorbic acid was determined before each exposure. NO2 exposure with placebo resulted in significant enhancement of airway responsiveness to methacholine aerosol (air-placebo 64 +/- 7 to NO2-placebo 53 +/- 8 mg/ml). Pretreatment with ascorbic acid prevented the significant alteration in airway responsiveness to methacholine aerosol (65 +/- 13 mg/ml, p less than 0.04). These results suggest that airway hyperresponsiveness induced by NO2 in normal subjects is completely prevented by pretreatment with ascorbic acid.
我们进行了一项双盲随机研究，以确定维生素C对正常受试者中二氧化氮诱导的气道高反应性的影响。11名正常受试者被随机分配接受4次实验性暴露的顺序。对于每次暴露，受试者服用维生素C（500毫克，每日4次，共3天）或安慰剂，随后暴露于清洁空气或2.0 ppm的二氧化氮中。获得了肺力学和气道对乙酰甲胆碱气雾剂反应性的测量结果。在每次暴露前测定血清抗坏血酸水平。安慰剂加二氧化氮暴露导致气道对乙酰甲胆碱气雾剂的反应性显著增强（空气-安慰剂组为64±7至二氧化氮-安慰剂组为53±8毫克/毫升）。抗坏血酸预处理可防止气道对乙酰甲胆碱气雾剂反应性的显著改变（65±13毫克/毫升，p<0.04）。这些结果表明，正常受试者中由二氧化氮诱导的气道高反应性可通过抗坏血酸预处理完全预防。
