Dexamethasone and prostacyclin biosynthesis by serosal membranes of the rabbit peritoneal cavity

The effect of 2.5 microM dexamethasone on prostacyclin biosynthesis in isolated peritoneal serosa of the rabbit was studied. Pretreatment with dexamethasone for 90 min or more led to suppression of the subsequent prostacyclin biosynthesis in the absence of dexamethasone. This inhibition and the formation of extracellular non dialysable inhibitors were dependent on protein biosynthesis. These results indicate that glucocorticoids can partly suppress prostacyclin biosynthesis, probably via formation of lipocortin-like activity.