Thyroxine-induced production of superoxide anion by human alveolar neutrophils and macrophages: A possible mechanism for the exacerbation of bronchial asthma with the development of hyperthyroidism

Bronchial asthma worsens after the development of hyperthyroidism. However, the biochemical mechanism of this phenomenon, which is induced by thyroxine (T-4), remains obscure. In the present study, we showed that T-4 directly stimulates lproduction of superoxide anion by alveolar neutrophils and macrophages. These cells, when sensitized with a patient's serum and then treated with both the patient's specific allergen and T-4, produced higher amounts of superoxide anion than did sensitized cells treated with the specific allergen or T-4 alone. Our data suggest that T-4 enhances production of reactive oxygen species by alveolar neutrophils and macrophages, which might play an important role in the exacerbation of bronchial asthma with the development of hyperthyroidism.