[Impact of ultrasound-mediated microbubbles on myocardial vascular permeability in rats].

OBJECTIVE: To investigate the impact of high-dose microbubbles induced by high mechanical index myocardial contrast echocardiography (MCE) on vascular permeability and its recovery time in rats. METHODS: Thirty male Wistar rats were randomized into 4 MCE groups (groups A-D) and a control group. In the MCE groups, Evans blue was injected at 10 s before MCE (A), immediately after the end of MCE (B), and at 5 min (C) and 20 min after the end of MCE (D). In the control group, the microbubbles and Evans blue were injected at the end of a 5-min ultrasound exposure. All the rats were sacrificed 5 min after Evans blue injection, and the content of Evans blue in the myocardium and the percentage of Evans blue leakage area were determined. RESULTS: The percentage of Evans blue leakage area in groups A, B and C were significantly higher than that in the control group (P<0.05), while the percentage was similar between group D and the control group (P>0.05). Evans blue contents in groups A and B were significantly higher than that in the control group (P<0.05), but groups C and D showed comparable contents with the control group E (P>0.05). No significant changes of the heart rates and premature beat number were observed during and after MCE in these groups (P>0.05). CONCLUSION: High mechanical index MCE and a high contrast dose may induce increased microvascular leakage in rats, and the vascular permeability can recover in 20 min after MCE.