Effect of stobadine on oxygen free radical generation in stimulated human polymorphonuclear leukocytes.

The generation both superoxide and a mixture of reactive oxygen species was recorded in a suspension of human polymorphonuclear leukocytes stimulated with phorbol myristate acetate. While stobadine dose-dependently decreased chemiluminescence, only its highest concentration used reduced significantly superoxide generation. The results suggest that stobadine is a more effective scavenger of free radicals rather than a quencher of superoxide anion.

Effect of stobadine on human stimulated polymorphonuclear leukocytes.

The effect of stobadine (0.1-100 microM) on human polymorphonuclear (PMN) leukocytes stimulated with N-formyl-methionyl-leucyl-phenylalanine, a specific receptor activator, or with the calcium ionophore, A-23187 (receptor bypassing stimulus) was investigated with respect to: i) superoxide generation, ii) beta-glucuronidase release and iii) 3[H]-arachidonic acid liberation. Stobadine was found to exert an inhibitory effect on N-formyl-methionyl-leucyl-phenylalanine but not on A-23187-stimulated PMN leukocytes.

Human polymorphonuclear leukocytes: effect of chloroquine on aggregation, arachidonic acid liberation and thromboxane B2 generation.

The effects of the antimalarial drug chloroquine (CQ) on arachidonic acid (AA) liberation from, thromboxane B2 (TXB2) formation in, and aggregation of isolated human polymorphonuclear (PMN) leukocytes stimulated with N-formyl-methionyl-leucyl-phenyl-alanine (FMLP) were investigated. CQ decreased aggregation of stimulated PMN leukocytes, however in contrast to AA liberation and TXB2 formation, lower concentrations were more effective than the highest one used. This effect may be associated with an increase in intracellular pH, reported to be induced by higher CQ concentrations, possibly counteracting the inhibition of aggregation, and/or eliminating negative feed back control of aggregation by lack of prostaglandins.