SSAO/VAP-1 participates in the accumulation of leukocytes at the site of inflammation. A new SSAO inhibitor, SzV-1287 was demonstrated to inhibit both acute and chronic inflammation in rats more effectively than the known enzyme inhibitor, LJP-1207. Surprisingly, the SSAO activity was not increased, but decreased both in acute and chronic inflammation. Though experiments are in progress to clarify these findings, the enzyme might play a role in the very early phase of inflammation and be inactivated during leukocyte extravasation.