Inhibition by nedocromil sodium of superoxide anion production in human neutrophils. A preliminary comunication

In this preliminary study, the effects of nedocromil sodium (3 or 300[mu]M) on the superoxide anion production and secretion of [beta]-glucuronidase and vitamin B12-binding protein were investigated using human neutrophils stimulated with N-formyl-methionyl-leucyl-phenylalanine (FMLP; 10 or 100nM) or phorbol-myristate-acetate (PMA; 100 [mu]g/L). production was significantly inhibited ([almost equal to]80%) in the presence of nedocromil sodium 300[mu]M, but only when a low dose of FMLP (10nM) was used. In contrast, nedocromil was without effect on production induced by high doses of FMLP (100[mu]M) or by PMA (100 [mu]g/L), and on secretion induced by either of these stimulants. Studies are in progress to ascertain whether this inhibitory effect on receptor mediated production can be related to the therapeutic effect of nedocromil sodium.