Abstract: Objective: To observe matrix reconstruction related regulating factors changing with time and research matrix reconstruction mechanism after acute myocardial infarction in rats. Methods: Ligating left anterior descending coronary artery of rats to make myocardial infarction model, the rats were killed on 1 day, 3 days, 7 days, 14 days, 28 days separately after operation, using Masson dyeing to detect collagen volume fraction (CVF) in non-infarcted area; Gelatinases spectrum method to detect MMP-2, TIMP-2 activity; Real-time fluorescence quantitative polymerase chain reaction (PCR) to detect mRNA expression of NF-ΚB and TNF-α.Results: Compared with Sham operation group, CVF in non-infarcted area increased with time in infarction group, most obviously 28 days after infarction (P<0.01); activity of MMP-2 and TIMP-2 increased with time, both of them reached peak 14 days after infarction then decreased, but remained more active than Sham operation group by 28 days (P<0.05); expression of TNF-αreached peak 7 days after infarction then decreased, continuing to 28 days after infarction, still higher than Sham operation group (P<0.05); expression of NF-κ B increased with infarction time(P<0.05, P<0.01). Conclusions: Activity changes of MMP-2、TIMP-2 and related regulating factors complied obviously with infarction time, it might be an important mechanism of matrix reconstruction in non-infarcted area after acute myocardial infarction in rats.

Key words: Non-infarcted area, Matrix reconstruction, Time window, TNF–α, NF - κ B