ROLE OF PLATELET-ACTIVATING-FACTOR ON THE FIBRINOLYTIC ACTIVATION IN THE PATHOGENESIS OF GASTRIC-MUCOSAL DAMAGE INDUCED BY ENDOTHELIN-1

We have examined the hypothesis that the release of tissue type plasminogen activator may play a prominent role in endothelin induced gastric mucosal injury. We determined tissue type plasminogen activator activity in the regional blood sample and the concentration of platelet activating factor in the gastric mucosa after the administration of endothelin-1 in a range of 50-500 pmol/kg into the left gastric artery of male Wistar rats. Endothelin-1 increased the tissue type plasminogen activator release and platelet activating factor formation, and induced subsequent gastric mucosal haemorrhagic change in a dose dependent manner. In addition CV-6209, a selective platelet activating factor blocker, attenuated the activation of regional tissue type plasminogen activator and the development of mucosal damage induced by endothelin-1. The results of this study showed that tissue type plasminogen activator activation may play an important role in the pathogenesis of endothelin induced mucosal injury of rat stomach, and suggest that the platelet activating factor may be involved in the process of regional fibrinolytic activation induced by endothelin-1.