Effect of eplerenone on cardiac fibroblast differentiation in rats after acute myocardial infarction

Abstract

Objective To investigate the effect of eplerenone on the cardiac fibroblast differentiation in rats after acute myocardial infarction (AMI). Methods By ligating the left coronary artery in male SD rats, the rat model of AMI was established and randomly divided to AMI group (n=11), eplerenone group (n=13) and sham-operated group (n=13). Rats in eplerenone group were given eplerenone 30 mg·kg-1·d-1 and the other two groups were given deionized water for 4 weeks. Myocardial collagen fiber area was measured after Masson′s trichrome staining and myocardial collagen volume fraction (CVF) and perivascular collagen area (PVCA) were calculated. Alkaline hydrolysis method were used to determine myocardial hydroxyproline (Hyp) content, and myocardial α-smooth muscle actin (α-SMA) expression was detected by Western Blot. Results Compared to rats in sham group, there were significant increases in myocardial Hyp contents [(420.11±58.24) μg/g vs. (513.7±73.46) μg/g], CVF[(4.17±0.41)% vs. (5.59±0.73)%] and PVCA[(1.12±0.21)% vs. (2.34±0.47)%] in rats in AMI group (all P<0.01). In comparison with rats in sham group, the expression of myocardial α-SMA also increased in rats in AMI group (0.46±0.15 vs. 1.49±0.37, P<0.01). Compared with rats in AMI group, there were significant decreases in myocardial Hyp contents [(513.7±73.46) μg/g vs. (441.1±82.65) μg/g], CVF[(5.59±0.73)% vs. (5.02±0.56)%] and PVCA [(2.34±0.47)% vs. (1.93±0.39)%] in rats treated with eplerenone (all P<0.05). In comparison with rats in AMI group, the expression of myocardial α-SMA also decreased in rats treated with eplerenone (1.49±0.37 vs. 1.18±0.31, P<0.05). Conclusion Eplerenone may play a role in anti-myocardial fibrosis by inhibiting cardiac fibroblastthe differentiation. Key words: Acute myocardial infarction; Myocardial fibrosis; Cardiac fibroblast; Eplerenone