• ageing;
  • alveolar macrophages;
  • guinea-pig;
  • superoxide radicals;
  • platelet-activating factor


To study the effect of maturation on abilities of superoxide radicals (O−2) generation in the airways, we compared stimuli-induced O−2 generation by alveolar macrophages in immature (aged 10±2 days) and adult (aged 90±2 days) guinea-pigs. The production of O−2 was assayed by chemiluminescence method, using aCypridina luciferin analog as a highly sensitive and specific probe for O−2. Whereas no significant difference in cell components of bronchoalveolar lavage fluid was observed between immature and adult animals, O−2 generation induced by stimulation of alveolar macrophages was greater in immature than in adult animals, with significant differences observed after platelet-activating factor (100nM) or phorbol myristate acetate (0.5μg/ml). The results suggest that alveolar macrophages from immature animals are far more potent O−2 generators than the same cells of adult animals.