ABILITY OF POLYMORPHONUCLEAR LEUKOCYTES TO GENERATE ACTIVE OXYGEN SPECIES IN ASTHMATIC CHILDREN

Abstract

I have investigated the ability of peripheral polymorphonuclear leukocytes (PMN) from children with bronchial asthma and control subjects to generate superoxide anion (O-2) and other active oxygen species using 2-methyl-6- (p-methoxyphenyl) -3, 7-dihydroimidazo [1, 2-a] pyrazin-3-one (MCLA), a sensitive and specific chemiluminescence (CL) probe for O-2, and luminol-dependent CL methods. The ability of PMN from subjects with asthma to generate O-2 and other active oxygen species was significantly greater than that of PMN from control subjects when stimulated with opsonized zymosan (OZ), phorbol myristate acetate (PMA) or N-formyl-methionyl-leucyl-phenylalanine (FMLP).Furthermore, in the same asthmatic children, the generation of O-2 and other active oxygen species was significantly higher with attacks than without attacks when PMN were stimulated with OZ. I also demonstrated that O-2 generation correlated with the degree of bronchial hyperresponsiveness (BHR) to inhaled histamine. These results suggest that PMN from asthmatic children, especially those with attacks, generate more active oxygen species than those from control subjects and that airway inflammation caused by O-2 may be closely related to BHR in subjects with bronchial asthma.