Changes of expressions of VEGF, bFGF, and angiogenesis, and effect of benazepril, bFGF on angiogenesis in acute myocardial infarction model of the rabbits.

OBJECTIVE

To explore the changes of vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF) and angiogenesis, and the effects of bFGF, angiotensin converting enzyme inhibiter(ACEI) benazepril on the angiogenesis in acute myocardial infarction (AMI) model of rabbits, and to provide a probable evidence for the treatment of AMI.

METHODS

AMI model was established by ligating anterior descending branch of coronary artery of Japan-Sino hybridization white rabbits. The postoperative rabbits were randomly divided into 6 groups and each group was treated with different drugs. Groups 1 and 2 were treated with normal saline (NS) for 28 and 14 days (d), group 3 and 4 with bFGF for 28 and 14 d, groups 5 with benazepril for 14 d, and group 6 with benazepril and bFGF for 14 d respectively. The rabbits were killed on the 14th or 28th d and their hearts were excised, sectioned and stained with HE, Masson trichrome to observe VEGF, bFGF and CD(34) under a microscope, which were quantified with a computer-assisted morphometry.

RESULTS

Compared with group 1, the granulation tissue of infarction zone (IZ) in group 2 freshened up, and the capillary density (CD) in IZ was increased (P = 0.002). The CD in the IZ as well as VEGF and bFGF in groups 3 and 4 were increased respectively (P = 0.011-0.037). In group 5 the changes of VEGF and bFGF were not found in the IZ and the border zone (BZ) while CD was significantly increased (35.4% and 25.6%, P = 0.036 and 0.037). Compared with group 2, the CD in the IZ and BZ of group 6 was significantly increased (63.4% and 44.3% P = 0.007 and 0.007), meanwhile VEGF and bFGF were increased. Compared with group 5, only VEGF was increased.

CONCLUSION

Intravenous bFGF may increase VEGF and bFGF significantly, thus promoting the angiogenesis in the IZ and BZ in cardiac infarction as VEGF and bFGF are the potent angiogenic growth factors. Benazepril may promote angiogenesis in the IZ and BZ in cardiac infarction, but its mechanism is irrelative to the expression of VEGF and bFGF. The combination of benazepril and bFGF may promote, to some extent, the expression of VEGF and bFGF, but their effect on angiogenesis has not been found.