Influence of the inhalative aerosol Atrovent on airway resistance and intrathoracic gas volume in healthy volunteers of different ages.
53 healthy volunteers of different age groups were included in this study. Airway resistance (Rt) and intrathoracic gas volume (IGV) were measured with volume constant bodyplethysmograph before and 15, 30, 60 and 120 min after a 1-min exposure to Atrovent aerosol. There were statistically significant reductions in Rt in all four groups (group I: 4-11 years; group II: 18-30 years; group III: 32-45 years; group IV: 47-54 years) of volunteers. Statistically significant reductions in IGV were observed in groups I and II. Group III also showed reduction in IGV, but it was not statistically significant. In contrast we found light but statistically significant increase in IGV in group IV. When the values of Rt were computed as specific airway conductance, then the increases following atrovent aerosols were statistically significant only in groups I, II and IV, but not in group III. It is concluded that smooth muscle tones, as evident from Rt reductions following atrovent inhalation, were not uniform in all individuals and that age plays an important role in this mechanism. However, it is not clear whether nervous components alone or the physicochemical nature of smooth muscles are also the controlling factors.
D000293:Adolescent; D000328:Adult; D000336:Aerosols; D000375:Aging; D000403:Airway Resistance / Q000187:drug effects*; D001286:Atropine Derivatives / Q000494:pharmacology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D009241:Ipratropium / Q000494:pharmacology*; D008176:Lung Volume Measurements; D008297:Male; D008875:Middle Aged; D009130:Muscle, Smooth / Q000187:drug effects; D010276:Parasympatholytics / Q000494:pharmacology*; D010993:Plethysmography, Whole Body; D012119:Respiration / Q000187:drug effects
D000336:Aerosols; D001286:Atropine Derivatives; D010276:Parasympatholytics; D009241:Ipratropium