ABSTRACT
Aim To observe the effects of simvastatin on PPARγ and p65 subunit of NF-κB and to invest the mechanism of simvastatin preventing hypertrophy and keeping cardiac function.Methods 24 rabbits were divided into 4 groups.Rabbits received sham operation as health control in group I. In other groups, aortic regurgitation and coarctation of ascending aorta were operated in rabbits.Rabbits received no drugs in Group Ⅱ. In group Ⅲ, rabbits were given simvastatin 5 mg·kg~(-1)·d~(-1) after the operation for 8 weeks. In group Ⅳ, rabbits were given simvastatin 5 mg·kg~(-1)·d~(-1) after 4 weeks of operation for 4 weeks. At the beginning and the end of the experiment, left ventricular end diastolic pressure (LVEDP) was measured with catheter. At the end of the experiment, heart weight (HW), left ventricular weight (LVW), body weight (BW), heart weight/body weight radio (HW/BW radio), left ventricular weight/body weight radio (LVW/BW radio) were measured.The PPARγ mRNA expression was analyzed by RT-PCR. PPARγ and p65 protein expression in cardiomyocyte nuclear were analyzed through Western blot. The activity of p65 was analyzed with EMSA.Results The HW, LVW, HW/BW were significantly decreased in the early and late treatment group than in CHF group(P<0.05,P<0.01). The LVW/BW was significantly decreased inearly treatment group than in CHF group, too (P<0.01). The LVEDP was significantly decreased in the early and late treatment group than in CHF group (P<0.01). The mRNA and protein of PPARγ significantly fell in CHF heart (P<0.01). The activity and protein expression of p65 were significantly increased in CHF heart (P<0.01). Simvastatin increased the mRNA and protein expression of PPARγ and decreased the activity and protein expression of p65 (P<0.01).Conclusions Simvastatin inhibits the cardiac hypertrophy and improves cardiac function. The mechanism of simvastatin on cardiac remodeling and function relates to the increase of PPARγ expression and preventing the NF-κB activation.
ABSTRACT
Objective To compare the differences of cardiac function and interstitial remodeling between diastolic heart failure(DHF) and systolic heart failure(SHF) rabbit models. Methods To establish DHF model with abdo-mial aorta constriction and SHF model with abdomial aorta constriction plus aortic insufficiency. The cardiac func-tion was examined by UCG parameters and homodynamic parameters. The collagen content was measured through hydroxyproline colorimetric assay and shown as collagen area(CA), collagen volume fraction(CVF) and area ratio of Ⅰ to Ⅲ type collagen with PSR. Results Compared with control group, there were significantly increased thick-ness and stiffness of myocardium, impaired diastolic function but normal ejection fraction (EF), and significantly increased collagen content, CA, CVF and area ratio of Ⅰ to Ⅲ type collagen in DHF group; heart chamber was sig-nificantly enlarged, systolic function decreased, and collagen content, CA, CVF significantly increased, but ratio of Ⅰ to Ⅲ type collagen decreased in SHF group(P <0.05 or P <0.01). Conclusion DHF and SHF rabbit mod-els were established successfully, which can simulate clinical profiles and provide technical support to future re-search.