Effect of stobadine on human stimulated polymorphonuclear leukocytes

The effect of stobadine (0.1-100 mu M) on human polymorphonuclear (PMN) leu kocytes stimulated with N-formyl-methionyl-leucyl-phenylalanine, a specific receptor activator or with the calcium ionophore, A-23187 (receptor by pas sing 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-le ucyl-phenylalanine but not on A-23187-stimulated PMN leukocytes. The effect was more intensive on superoxide generation and beta-glucuronidase release than on (3)[H]-arachidonic acid liberation. These results indicate that th e inhibitory effect of stobadine is most probably via a mechanism dependent on signal transduction across the plasma membrane. This effect may occur t hrough inhibition of arachidonate signal transduction through a regulatory G-protein. (C) 1999 Prous Science. All rights reserved.