Zinc acexamate reduces gastric damage induced by platelet-activating factor.

We have tested the ability of zinc acexamate (ZAC) to prevent platelet-activating-factor (Paf) induced gastric damage in rats. Lesions were characterized by a vascular congestion affecting the entire mucosa, oedema, haemorrhage and frequent necrosis of the more superficial areas. The gastric damage appearing after Paf was accompanied by degranulation of gastric mast cells. Leukocytes were often seen at the submucosal level. Oral pretreatment with ZAC reduced in a dose-dependent manner both gastric damage and mast cell degranulation observed after Paf. ZAC administered orally at a dose of 100 mg kg-1 statistically inhibited (p less than 0.01) gastric damage and mast cell degranulation. ZAC did not affect the hypotension induced by Paf confirming that gastric damage and hypotension appearing in rats after Paf administration are two independent phenomena. The present findings indicate that the inhibitory effect of ZAC upon gastric lesions induced by Paf may be related to the different protective actions exhibited by this zinc compound in a wide variety of experimental models of gastric ulcer.