The Study On Pathogenesis And Drugs Prevention Effects Of Diastolic Heart Failure

Partâ… : Establishment and comparison in rabbit models with diastolic heart failure and systolic heart failureObjective: To establish the diastolic heart failure （DHF） and systolic heart failure （SHF） rabbit models respectively, and to compare the differences in cardiac function and ventricular remodeling between them.Methods: New Zealand white rabbits were randomly divided into three groups （n=8 in each group）: sham operation （SO） group, DHF group, and SHF group. The DHF model was established by abdomial aorta constriction, and the SHF model was established by aortic insufficiency. Cardiac function was measured by echocardiography and hemodynamic assays. The BNP （B-type brain natriuretic peptide）, NE （norepinephrine）, and EPI （epinephrine） were measured by Enzyme-Linked Immunosorbent Assays （ELISA）. The pathological stutas was observed by HE stain and VG stain. The collagen content （CC） was detected through hydroxyproline colorimetric assay and collagen area （CA）, collagen volume fraction（CVF） and area ratio ofâ… toâ…¢type collagen were detected by PSR stain.Results: After surgery 12 weeks, compared with the SO group, there was significantly increased ventricular wall thickness and stiffness, increased E/A and LVEDP, prolonged IVRT and tau （P<0.01）, but normal left ventricular ejection fraction （LVEF）, and significantly increasing CC, CA, CVF and area ratio ofâ… toâ…¢type collagen in DHF group（P<0.01）; there were significantly enlarged left ventricular chamber, decreased LVEF, increased LVEDP, and significantly increasing collagen content, CA, CVF but decreased ratio ofâ… toâ…¢type collagen in SHF group（P<0.05 or P<0.01）. Moreover, there were increased LAd, BNP, NE and EPI in both of DHF and SHF groups （P<0.01）.Conclution: The DHF and SHF rabbit models were established successfully, there was enlarged left ventricular chamber and unchanged ventricular wall thickness in the SHF model; whereas there was increased ventricular wall thickness and unchanged ventricular chamber in the DHF model, and more severe interstitial remodeling than that in the former.Partâ…¡: The differences in sarcoplasmic reticulum Ca²⁺ leak characters between systolic and diastolic heart failure rabbit modelsObjective: To compare the differences in Ca²⁺ leak characters and the expression and activities of the related proteins, and to investigate the potential mechanisms.Methods: The SR Ca²⁺ leak was measured with a calcium imaging device. The expression of FK-506 binding protein 12.6 （FKBP12.6）, Ca²⁺/calmodulin-dependent protein kinase II （CaMKII）, protein kinase A （PKA）, ryanodine receptor （RyR2） and its phosphorylation sites were evaluated by RT-PCR and Western blots. The activities of PKA and CaMKâ…¡were detected byγ-32P substrate incorporation.Results: Compared with the SO group, in the DHF group, there was reduced total amount of FKBP12.6 （P<0.05）, increased expression and activity of PKA （P<0.05 or P<0.01） and its phosphorylation site RyR2-P2809 in the RyR2 （P<0.05）, but no prominent Ca²⁺ leak; whereas in the SHF group, there was significantly enhanced SR Ca²⁺ leak （P<0.01）, reduced total amount of FKBP12.6 and association amount of FKBP12.6-RyR2 （P<0.05）, increased expression and activity of PKA and CaMKII and their phosphorylation status in the RyR2-P2809 and RyR2-P2815 （P<0.05 or P<0.01）.Conclution: In the SHF group, there was abnormal enhanced SR Ca²⁺ leak, but the prominent SR Ca²⁺ leak is not observed in DHF model, which may be one of the reasons in preserved systolic function, and CaMKII possibly plays more important role in SR Ca²⁺ leak.Partâ…¢: The differences in sarcoplasmic reticulum Ca²⁺ re-uptake function between systolic and diastolic heart failure rabbit modelsObjective: To compare the differences in calcium re-uptake function and the expression and activities of the calcium regulation related proteins, and to investigate the potential mechanisms.Methods: The SR Ca²⁺ re-uptake function was measured with a calcium imaging device. The expression of sarcoplasmic reticulum calcium adenodine triphosphatase2a （SERCA2a）, CaMKII, PKA, PP1α, phospholamban （PLB） and its phosphorylation site （Ser-16） were evaluated by RT-PCR and Western blots. The activities of PKA and CaMKâ…¡were detected byγ-32P substrate incorporation. Results: Compared with the SO group, there was reduced Ca²⁺ re-uptake amount （P<0.01） and the expression and activity of SERCA2a （P<0.05 or P<0.01）, increased the expression and activity of PKA and PP1αin both of DHF and SHF groups （P<0.05 or P<0.01）. In the DHF group, there was unchanged the expression of NCX, PLB and its phosphorylation site （Ser-16）; whereas in the SHF group, there was reduced expression of PLB and its phosphorylation site Ser-16 （P<0.05）, but significantly increased expression of NCX （P<0.05）.Conclution: There was reduced Ca²⁺ re-uptake function, reduced expression and activities of SERCA2a in both of DHF and SHF groups, and there was increased expression of NCX in the SHF group, whereas there were unchanged expression of NCX in the DHF group, which may be one of the reasons in different pathogenesis between the two HF models.Partâ…£: The effect of Atorvastatin on ventricular remodeling and expression of calcium regulatory proteins in the diastolic heart failure rabbit modelObjective: To investigate the effect of atorvastatin on ventricular remodeling and expression of calcium regulatory proteins in the diastolic heart failure rabbit model.Methods: New Zealand white rabbits were randomly divided into three groups （n=8 in each group）: sham operation （SO） group, DHF group, and atorvastatin group. The DHF model was established by abdomial aorta constriction, and the atorvastatin model was supplied as 5mg.kg-1.d-1 after the operation of abdomial aorta constriction 24 hours. Cardiac function was measured by echocardiography and hemodynamic assays. The pathological stutas was observed by HE stain and VG stain. The collagen content （CC） was detected through hydroxyproline colorimetric assay and collagen area （CA）, collagen volume fraction（CVF） and area ratio ofâ… toâ…¢type collagen were detected by PSR stain. The expression of SERCA2a, PKA and PP1αwere evaluated by Western blots.Results: After surgery 12 weeks, compared with the SO group, there was significantly increased IVSd, LVPWd and LAd, increased E/A and LVEDP, prolonged IVRT and tau （P<0.01）, but normal left ventricular ejection fraction （LVEF）, and significantly increased CC, CA, CVF and area ratio ofâ… toâ…¢type collagen （P<0.01）, reduced the expression of SERCA2a （P<0.05）, increased the expression of PKA and PP1α（P<0.05） in the DHF group. And IVSd, LVPWd, CC, CA, CVF in atorvastatin group were lower than those in the DHF group（P<0.01）, but little higher than those in the SO group（P<0.05 or P<0.01）, and the other data above-mentioned were unchanged in atorvastatin group. Conclution: Atorvastatin can significantly improve the pressure overload induced ventricular remodeling and regulate the expression of calcium regulatory proteins, thus it can postpone the whole pathological progression develop to DHF.Partâ…¤: The effect of Telmisartan on ventricular remodeling and expression of calcium regulatory proteins in the diastolic heart failure rabbit modelObjective: To investigate the effect of telmisartan on ventricular remodeling and expression of calcium regulatory proteins in the diastolic heart failure rabbit model.Methods: New Zealand white rabbits were randomly divided into three groups （n=8 in each group）: sham operation （SO） group, DHF group, and telmisartan group. The DHF model was established by abdomial aorta constriction, and the telmisartan model was supplied as 10mg.kg^-1.d^-1 after the operation of abdomial aorta constriction 24 hours. Cardiac function was measured by echocardiography and hemodynamic assays. The pathological stutas was observed by HE stain and VG stain. The collagen content was detected through hydroxyproline colorimetric assay and collagen area （CA）, collagen volume fraction（CVF） and area ratio ofâ… toâ…¢type collagen were detected by PSR stain. The expression of SERCA2a, PKA and PP1αwere evaluated by Western blots.Results: After about surgery 12 weeks, compared with SO group, there was significantly increased IVSd, LVPWd and LAd, increased E/A and LVEDP, prolonged IVRT and tau （P<0.01）, but normal left ventricular ejection fraction （LVEF）, and significantly increased CA, CC, CVF and area ratio ofâ… toâ… type collagen （P<0.01）, reduced the expression of SERCA2a （P<0.05）, increased the expression of PKA and PP1α（P<0.05） in the DHF group. And IVSd, LVPWd, CC, CA, CVF in telmisartan group were lower than those in the DHF group（P<0.01）, but little higher than those in the SO group（P<0.05 or P<0.01）, and the other data above-mentioned were unchanged in telmisartan group.Conclution: Telmisartan can significantly improve the pressure overload induced ventricular remodeling and regulate the expression of calcium regulatory proteins, thus it can postpone the whole pathological progression develop to DHF.