ISSN:
1432-1246
Schlagwort(e):
NO2 effects
;
Diffusion
;
Distribution of perfusion
;
Resistance
;
Scintigraphy
Quelle:
Springer Online Journal Archives 1860-2000
Thema:
Medizin
Notizen:
Summary The acute influence of NO2 in MAC value concentrations upon the pulmonary function was studied in 55 healthy male subjects (18–65 years old) and 84 male patients suffering from chronic bronchitis (30–72 years old). The latter were admitted to the hospital because of an exacerbation of their disease. Additionally, the distribution of lung perfusion before and after inhalation of NO2 concentrations between 30 and 50 ppm was determined by scintigraphy in rabbits. These studies resulted in the following: 1. An inhalation of 5 ppm NO2 over 15 min led to a significant decrease of the CO diffusing capacity. In 16 healthy subjects, the mean decrease of D LCOwas by 3.8 ml · min−1 · torr−1 (p〈0.01). 2. A prolongation of the exposure period in chronic bronchitics from 15 to 60 min at a NO2 concentration of 5 ppm did not result in a disturbance of the respiratory gas exchange for oxygen beyond the extent of the disturbance observed after exposure to 5 ppm NO2 over 15 min (p〉0.1). 3. For the concentration range up to 5 ppm, a relationship between the inhaled concentration of NO2 and the increase of airway resistance was obvious; no effect seemed to be in concentrations 〈1.5 ppm. 4. No correlation was found between the increase of R tafter the inhalation of NO2 as dependent upon the initial value of airway resistance. 5. In the lungs of the rabbit, scintigraphy revealed that an inhalation of 30 ppm NO2 over 15 min resulted in a re-distribution of perfusion showing a reduced storage of activity in the peripheral areas of the lungs. These findings are discussed with a view to a causative association between air pollution, inhalation of tobacco smoke, chronic bronchitis, and pulmonary emphysema. Taking into account experimental studies in animals, the authors feel that the impairment of pulmonary functions observed after acute inhalation of low concentrations of NO2 if frequently repeated over a number of years may have, together with other causative factors, an influence upon the development and maintenance of chronic bronchitis including pulmonary emphysema.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1007/BF00538974
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