Experimental study of urokinase concentration after in vivo thrombolysis with urokinase targeting microbubbles combined with ultrasound / 中华超声影像学杂志

ABSTRACT

Objective:To prepare urokinase targeted thrombus microbubbles combined with low frequency ultrasound to dissolve thrombus in rabbit femoral artery, and to explore the mechanism of thrombolysis through the change of urokinase concentration.Methods:Twenty-four rabbits with thrombosed femoral artery were randomly divided into four treatment groups urokinase alone (UK) group, ultrasound with non-targeted microbubble and urokinase (US+ M+ UK) group, platelet-targeted microbubble with urokinase (R+ UK) group, ultrasound with platelet-targeted microbubble and urokinase (US+ R+ UK) group. Thrombus-targeted microbubbles were injected through the ear vein and irradiated by ultrasound for 30 minutes, and the pulsed Doppler blood flow meter was used to continuously monitor the blood flow at 0 min, 10 min, 20 min, 30 min, 60 min, 90 min and 120 min after injection. At the same time, the changes in urokinase concentration were monitored, and the characteristics of blood flow and urokinase concentration changes were analyzed.Results:UK and US+ M+ UK groups failed to show recanalization at 120 minutes after treatment.In contrast, the US+ R+ UK and R+ UK groups both achieved persistent recanalization( P<0.001). Compared with the basal state. Both the R+ UK group and R+ UK+ US group showed a decrease at 60 minutes, and the difference was statistically significant( P<0.05). Conclusions:In the thrombolysis process of low-frequency ultrasound combined with a targeted contrast agent carrying urokinase, the targeting can make the local urokinase concentration of thrombus reach the highest level. At the same time, ultrasound and targeted microbubbles promote urokinase to enter the thrombus, and finally achieve the strongest thrombolytic effect.