The relationship between gene expression of MMP-2 and TIMP-1,2 with atrial enlargement and atrial fibrillation during heart failure.

Objective To study the relationship between gene expression of MMP-2 and TIMP-1,2 with atrial enlargement and atrial fibrillation(AF) during heart failure(HF). Methods 14 mongrel dogs were randomized into HF induced by ventricular tachypacing and control group. Burst atrial pacing was used to induce AF. And the mRNA and protein level of MMP-2 and TIMP-1,2 were detected by reverse transcription-polymerase chain reaction and immunohistochemical technique. Atrial systolic area were measured by transthoracic echocardiography before atrial specimen been collected. Results Compared with control group, left ventricular ejection fraction decreased , The inducible rate and sustained time of AF increased in HF group;atrial size of HF group was markedly greater than the controls.The mRNA and protein level of MMP-2 increased evidently in both left atrial(LA) and right atrial (RA), TIMP-2 mRNA decreased in LA and had no change in RA and its protein had no change in both atrium,whereas the ratio of MMP-2/TIMP-2 of mRNA and protein increased markedly in both LA and RA of HF group. Both mRNA and protein level of TIMP-1 decreased significantly in both LA and RA of HF group. The lasting time of AF has a positive correlation with area of LA during HF(r=0.806,P=0.029). Conclusions The changes of MMP-2 and TIMP-1,2 gene expression and the unbalance of MMP-2/TIMP-2 appear to be a molecular mechanism of atrial enlagement and AF during HF.