Effect of IFN-γ on the expression of Matrix Metalloproteinase-9 and ventriculer remodeling in spontaneously rats

Objective:To investigate the effect of IFN-γ(IFN ppar-gamma)on the expression of Matrix Metalloproteinase-9(MMP-9) and ventriculer remodeling in spontaneously hypertensive rats(SHR).Methods:28 SHR(male) were randomly divided into 4 groups(each group=7) : high dose group(SHR-H),middle dose group(SHR-M),low dose group(SHR-L) and SHR control group(SHR-C);The other 7 WKY rats(male) as the negative control group(WKY).SHR-L group,SHR-M group,SHR-H group were respectively applied of IFN-γ(50 000 units/kg,100 000 units/kg,150 000 units/kg)daily morning intraperitoneal injection for 8w.As well,SHR-C group and WKY group were respectively applied of same amount of saline for eight weeks.Respectively the before treatment and after treatment 4,8w,caudal artery systolic blood pressure(SBP)were measured by the tail sleeve,MMP-9 serum content were detected by ELISA method.By the 8w,putting to death rats,we weighed the left ventricular mass(LVM) and calculated the left ventricular mass index LVMI(LVMI=LVM/BW).In the myocardial tissue the morphological changes were observed with HE staining and MMP-9 protein expression was analysed by Werstern blot.Results: The SHR group caudal artery systolic blood pressure(SBP),LVM,LVMI and MMP-9 serum content was significantly higher in all SHR group than WKY group(P0.05).Application of IFN-γ,SBP [(189.57±5.06)vs.(201.57±5.74)mm Hg(1 mm Hg=0.033 kPa)],LVMI[(2.68±0.08)vs.(2.89±0.08) mg/g],MMP-9[(3.20±0.35)vs.(4.90±0.51)mg/L](P0.05),MMP-9 protein in the myocardial tissue were significantly negative control expression[(0.49±0.07)vs.(1.05±0.08)](P0.05).Conclusion: IFN-γ can inhibit MMP-9 expression in myocardial tissue,improve hypertension ventricular remodeling,and may be associated with inhibition of myocardial chronic inflammation.