| [Objectiv]Today the therapy of the congestive heart failure has a large development,the mortality has a sharp decreasement,but it is not enough in the development of heart failure contral. Our experiment is to observe the relationships of peroxisome proliferator-activated receptor(PPARa) agonist Fenofibrate(FF) on energy metabolism in isoproterenol(Iso) induced chronic heart failure model.[Methods](一) Construct the rat heart failure model:The SD rats are separated into 4 groups. Contral group includes 10 pieces and Heart failure group includes 20 pieces weighted by 200-300g for each, (1)Contral group:subcutaneous injected equal physiological saline once every day for 4 weeks; (2) low dose ISO group:subcutaneous injected ISO 2 mg/kg/d; (3) medium dose ISO group:subcutaneous injected ISO 2.5mg/kg/d; (4) large dose ISO group:subcutaneous injected ISO 3mg/kg/d; Then establish CHF model and evaluate the rats survival rates after 4 weeks, receive the pathological structure characters of the rats myocardial observation for each group. We also evaluate the rats'heart function by Cardiac Doppler, the serum BNP level and the calculation of heart weight index, and try to find the perfect dosage of the rats heart failure model.Drug intervention study:The 30 pieces male rats which weighted by 200-300g for each are separated for 3 groups by random (n=10),and are injected by equal NS:1. the control group: normal raising, subcutaneous injection of equal NS everyday;2. sanofi bate protecting group:normal raising, FF group is continuously given the ethanol precipitation of suspension of sanofi bate by 100mg/kg/d for 4 weeks; 3. ISO damaged group:normal raising, given the subcutaneous injection of ISO (2.5mg/kg/d) for 4 weeks. Heart Function Evaluation:Cardiac Doppler: The Ultra-sound examinations, including the LVEDD, LVESD LVEF and FS, are done for the rats in the 2nd,3rd and 4th week after 0.3% sodium pentobarbital abdominal injection for anesthesia.Serum BNP: Test the serum BNP from the eyeball of rats by the 2nd,3rd and 4th week.At the end of the 4th week, after the general anesthesia, the centrifugal serum is acquired by the intubation to the carotid artery, and the heart samples are taken by anatomy and fixed into the 10% formaldehyde for 24h. After Conventional drawn, dehydrated, embedded in paraffin, 1mm intervals along the long axis of the left ventricular cross-sectional slices were cut 3, HE staining, optical microscope. The remaining myocardial tissues for each group are kept in the liquid nitrogen.Observation SignCardiac Doppler: Test of the LVEDD, LVESD, LVEF and FS.Myocardial pathological slice:The observation of the changes of the myocardial pathological structure changes of the rats under optical microscope.Heart weight index:Wash the remaining blood of heart by the cooled NS, cut the peripheral vascular and connective tissues., dry the water and weight the heart. Heart weight index=Heart damp weight/body weight.Serum: ELISA test used for the serum BNP and compared with the free fatty acid reference kit method to test the serum free fatty acid level.Heat tissue:Compared with the free fatty acid reference kit method to test the serum free fatty acid level, Spectrophotometric detection of myocardial tissue content of lactate and pyruvate, Western blot test the protein expression of PPARα,UCP2.Result1,Construction of the heart failure modelIn the large dose(3mg/kg/d) group,the number of the dead rats is fourteen at the end of four weeks, in the low dose(2mg/kg/d) group,there has no rat died ,in the medium dose(2.5mg/kg/d) group, there has two rats died,the survival rates of the above three groups are 30%,90% and 100%. Compared with control group,the LVEDD,LVESD,BNP andheart weight/body weight ratio have an obvious increment, LVEF and FS decreased (all P<0.01).The more dose of the ISO injected,the bigger of the LVEDD,LVESD,BNP,heart weight/body weight ratio are (all P<0.01), the less of the LVEF and FS are (all P<0.05).Although the level of the heart failure in the large dose(3mg/kg/d) is more serious,the survival rate has a sharp decrement.The dose of 3mg/kg/d is the better dose in contructing heart failure model.2,Heart structure and heart functions changesAt the end of the 4TH week, LVESD and LVEDD of the ISO damaged group and the FF protecting group is obviously larger than the control group (all P<0.05) Compared with the FF protecting, the LVEDD and LVESD of ISO damaged group is obviously larger (all P＜0.05); the LVEF and FS is obviously lower than the control group; compared with the FF group, the LVEF and FS of ISO damaged group is obviously decreased (all P<0.05)3,The myocardial pathological structure changesCompared with the control group and FF protecting group, the hypertrophy of the myocardial cells and partly are Acidophilic degeneration and (or) necrosis. The pathological changes are in lesions or in diffuse distribution. Hyperplasia of the connective tissues which is formed as cord happened in part of the rats.4,The Heart weight indexThe FF protecting group and the ISO group (3.16±0.12,3.58±0.08) are in large differences in the index comparing with the control group (2.13±0.15) Compared with the FF protecting group(3.16±0.12), the ISO group(3.58±0.08) is much higher (P＜0.01)5,Serum BNPThe FF protecting group and the ISO damage group (1.79±0.09,4.86±0.12) are in large differences comparing with the control group (0.39±0.03) in the level of serum BNP. Compared with the FF protecting group(1.79±0.09), the ISO group serum BNP(4.86±0.12) is much higher (P<0.01)6,Serum FFA and myocardial FFAThe FF protecting group and the ISO damage group re in large differences comparing with the control group in the level of serum FFA and myocardial FFA (all P<0.01). Compared with the FF protecting group, the ISO group serum FFA and myocardial FFA is much higher (all P＜0.01) 7,Myocardial lactic acid and pyruvateThe FF protecting group and the ISO damage group re in large differences comparing with the control group in the level of myocardial lactic acid and pyruvate (all P＜0.01). Compared with the FF protecting group, the ISO group myocardial lactic acid and pyruvate is much higher (all P<0.01)8,Heart tissue PPARaThe FF protecting group and the ISO damage group (614.13±87.08,160.34±14.12) are in large differences comparing with the control group (1586.69±93.44) (all P＜0.01). Compared with the FF protecting group, the ISO group heart tissue P P A Rαis much lower (P<0.01)9,Heart tissue UCP2The FF protecting group and the ISO damage group (637.28±73.14,1217.09±81.88) are in large differences comparing with the control group (435.56±63.18) (all P＜0.01). Compared with the FF protecting group, the ISO group Heart tissue UCP2 is much higher (P＜0.01)Conclusion1.During the progressive course of chronic heart failure, the myocardial fatty acid utilization barriers and the decreased energy by resolving the coupling of mitochondrial oxidative phosphorylation2.Peroxisome proliferator activator receptor(sanofi bate) is functioned in reducing the serum free acid, reducing the myocardial UCP2 expression so that improve the failure myocardial energy metabolism, inhibit the ventricular reconstruction and protect the myocardial function. |
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