抄録
We examined the mechanism of the synergistic action of elastase and hydrogen peroxide on vascular endothelial cell injury, using cultured endothelial cells prelabeled with 51Cr. Co-existence with elastase (10 μg/ml) and hydrogen peroxide (50 μM) induced severe endothelial cell injury, although each one of them alone had no such cytotoxicity at all. This synergistic effect was not based on the suppressed activities of the protective enzymes against oxidative stress, such as catalase and glutathione peroxidase, but related to hydroxylradicals, because this injury was inhibited by deferoxamine mesylate. Moreover, α-1 antitrypsin and α-2 macroglobulin, which are physiologically present in the serum as protease inhibitors, showed protective action on the synergistic effect.
Therefore, some protease inhibitors may be benificial to the diseases related to activated leukocytes, because they will suppress the endothelial cell injury elicited by active oxygen species released from leukocytes by inhibiting protease activity of leukocytes.
