RESUMO
AIM:To investigate the effects of irbesartan on the expression of hepatocyte growth factor (HGF) at mRNA and protein levels in rats with myocardial infarction (MI), and to explore the mechanisms of irbesartan attenuating myocardial fibrosis.METHODS:The male Wistar rat model of MI was successfully established.The surviving rats 24 h after the operation were randomly divided into 3 groups:model group,irbesartan group and sham group, with 9 rats in each group.The rats in irbesartan group were treated with the solution of irbesartan (50 mg·kg-1·d-1) by intragastric administration, while the rats in model group and sham group received the equal volume of saline by the same way.The body weight and left ventricle mass (LVM) of the rats were measured at the 4th week after operation, and the pathological changes of the ischemic myocardium were observed with HE staining.Meanwhile, the expression of HGF at mRNA and protein levels was detected by RT-qPCR and Western blot.RESULTS:HE staining showed that the myocardial cells in sham group were in neat arrangement, while the cardiac structure in model group and irbesartan group was in disorder.The pathological changes in irbesartan group were less than that in model group.No difference in the body weight at the 4th week after operation was observed, while the LVM was significantly different among the 3 groups (P<0.01).The LVM in model group was higher than that in sham group (P<0.01), and that in irbesartan group was higher than that in sham group (P<0.05).The LVM in irbesartan group was lower than that in model group (P<0.05).The expression of HGF at mRNA and protein levels was detected in each group.The expression of HGF at mRNA and protein levels in irbesartan group was higher than that in sham group (P<0.05), and that in model group was higher than that in sham group (P<0.01).Moreover, the mRNA and protein levels of HGF in irbesartan group were lower than those in model group (P<0.05).CONCLUSION:The LVM of MI rats with the treatment of irbesartan was reduced obviously at the 4th week after operation, and the pathological changes were also improved.At the 4th week after the operation, the treatment of irbesartan inhibited the expression of HGF at mRNA and protein levels.