Roles of oxygen radicals and elastase in citric acid-induced airway constriction of guinea-pigs

摘要

1. Antioxidants attenuate noncholinergic airway constriction. To further investigate the relationship between tachykinin-mediated airway constriction and oxygen radicals, we explored citric acid- induced bronchial constriction in 48 young Hartey strain guinea-pigs, divided into six groups: control; citric acid; hexa (sulphobutyl) fullerenes + citric acid; hexa (sulphobutyl) fullerenes + phosphor- amidon + citric acid; dimethylthiourea (DMTU) + citric acid; and DMTU + phosphaoramidon + citric acid. Hexa (sulphobutyl) fullerenes and DMTU are scavengers of oxygen radicals whilephosphor- amidon is ani nhibitorofthe major degradation enzyme for tachykinins.