Effect of dexamethasone on alpha 1-proteinase inhibitor synthesis in human cells of monocytic origin.

In this study we provide evidence for downregulation of alpha 1-Proteinase Inhibitor (alpha 1-PI) synthesis in cells of monocytic origin by the glucocorticoid analog, dexamethasone. This factor significantly reduced the basal level of alpha 1-PI expression as well as antagonized the effect of lipopolysaccharide and interleukin-6, stimulators of alpha 1-PI synthesis in cells of monocyte/macrophage lineage. Since increased levels of all of these mediators are observed in both acute infections and inflammatory reactions, their combination may affect the contribution of monocytes to the synthesis of alpha 1-PI.