Measurement of urokinase activity using thrombelastgraph and stability of urokinase preparations in solutions.

Abstract

The fibrinolytic activities of some commercially available urokinase preparations were compared using thrombelastgraph, and relationships between the stability of urokinase activity and additives contained in preparations, and between the specific activity and the difference of molecular weight of urokinase were studied.Results were as follows: 1) low molecular weight urokinase (LUK) was more stable than high molecular weight urokinase (HUK) . 2) HUK was kept most stable, when albumin was added.3) The stability of LUK did not depend on additives.4) When the urokinase solution was freezed and then thawed, specific activity of gelatinadded HUK was decreased to 50%, and that of albumin-added HUK to 90%.It was proved that the fibrinolytic activity of urokinase could be measured by thrombelastgraph.