Objective: To assess the effects of tongxinluo on vascular endothelial integrity and myocardial no-reflow in early reperfusion of acute myocardial infarction.
Methods: Forty mini-swines were divided into five groups randomly, sham group, control group, low dose (0.1 g/kg), medium dose (0.2 g/kg) and high dose (0.4 g/kg) groups of Tongxinluo. It was administered at 2 hours pre-reperfusion. Animals except in sham group were subjected to 1.5 hour of coronary occlusion followed by 3 hours of reperfusion. Content of VE-cadherin, beta-catenin, matrix metalloproteinase (MMP)-2 and 9 in myocardium were evaluated; no-reflow area was examined with myocardial contrast echocardiography (MCE) at 1.5 hour of AMI and 3 hours of reperfusion.
Results: (1) Compared with that of normal myocardium, content of VE-cadherin and beta-catenin decreased in reperfusion and no-reflow myocardium while MMP-2 and 9 increased significantly (all P < 0.05); (2) Compared with that of control group, a high dose of Tongxinluo could increase significantly the content of VE-cadherin in both reperfusion and no-reflow myocardium, (22.2 +/- 3.2)% vs (32.0 +/- 3.9)% and (14.5 +/- 2.8)% vs (28.3 +/- 2.2)% respectively, beta-catenin, (20.5 +/- 3.5)% vs (27.3 +/- 2.9)% and (13.3 +/- 2.1)% vs (20.6 +/- 2.4)%, while reduce MMP-2, (48.3 +/- 4.1)% vs (29.4 +/- 3.5)% and (57.3 +/- 4.3)% vs (38.2 +/- 4.0)% respectively, MMP-9, (55.6 +/- 4.0)% vs (34.3 +/- 3.5)% and (62.4 +/- 4.8)% vs (44.4 +/- 4.1)%, all P < 0.05; (3) Compared with that of control group, a high dose of Tongxinluo could reduce significantly both no-reflow area, (6.6 +/- 1.7) cm2 vs (4.7 +/- 1.5) cm2, P < 0.05, and percentage (90.8 +/- 3.8)% vs (71.4 +/- 4.1)%, P < 0.05, at 3 hours of reperfusion.
Conclusion: A high dose of tongxinluo could effectively maintain the integrity of vascular endothelium and attenuate no-reflow area in early reperfusion of acute myocardial infarction.