STAUROSPORINE INDUCES DE-NOVO SYNTHESIS OF PROSTAGLANDIN-H SYNTHASE-2IN RAT ALVEOLAR MACROPHAGES

This study was initiated to investigate the possible involvement of pr ostaglandin H synthase in the staurosporine-induced prostaglandin prod uction. The time course of prostaglandin H synthase activity in macrop hages treated with staurosporine (20 nM) showed that the maximum activ ity was reached in 20 h. The stimulatory effect of staurosporine on th romboxane B-2 production was maximum at 50 nM. staurosporine and this effect was reversed at higher concentrations. Immunoprecipitation of S -35-labeled enzyme using an antibody specific for prostaglandin H synt hase-2 paralleled the changes in enzyme activity. These results indica te that increased de novo synthesis of prostaglandin H synthase-2 is l argely, if not solely, responsible for staurosporine-stimulated prosta glandin production in macrophages.