抄録
The effects of dexamethasone and prednisolone on the prostacyclin synthesis, protein synthesis and cell size of cultured human endothelial cells were studied.
Inhibitory activity of endothelial cells treated with dexamethasone on ADP induced platelet aggregation was reduced, when compared with the non-treated endothelial cells. This observation showed that dexamethasone blocked prostacyclin synthesis in cultured endothelial cells.
Cell surface area after culturing the cells with dexamethasone or prednisolone for 48h were calculated by using image analysing system. The mean surface area of the endothelial cell treated with 10μM dexamethasone was 1.63 times greater than that of the untreated endothelial cell. The morphological change of endothelial cells was associated with an increase in protein synthesis without an increase in DNA synthesis or cellular replication. These effect of dexamethasone on morphological alteration and protein synthesis of the endothelial cells were completely inhibited by a protein inhibitor, cycloheximide.
Our results indicate that dexamethasone inhibits the prostacyclin formation in the cultured endothelial cell and can increase endothelial cell size. These effects of glucocorticoids are compatible with hemostatic effect in the thrombocytopenic state.
