Inhibition of Hyaluronidase by Urinary Kallikrein

INVESTIGATIONS have shown that crude kallikrein prepared from human urine and human serum possesses in vivo spreading properties which cannot be attributed to hyaluronidase activity1–3. Turbidimetric4, mucin clot5 and viscosimetric6procedures reveal that urinary kallikrein unlike hyaluronidase does not depolymerize hyaluronic acid. On the contrary, a marked inhibition of testicular hyaluronidase occurs when kallikrein is combined with the enzyme. In order to define further the properties of kallikrein, we investigated in vitro the effect of a urinary preparation on hyaluronidase.