| Objective: To explore the mechanism of total flavones ofhippophae rhamnoides (TFH) ameliorating cardiac hypertrophythrough the calcineurin signal pathway. Method:32rats were partiallybanded abdominal aortic artery to establish the hypertensive models andwere divided into four groups randomly (n=8):Control group (potablewater10ml.kg-1.d-1);Captoprill(CP) group(100mg.kg-1.d-1); TFH group(30mg.kg-1.d-1); Combination(Com) group(CP60mg.kg-1.d-1+TFH20mg.kg-1.d-1).they were gastric perfused once a day for6weeks.Other8rats with sham-operation were setted as Sham group(potable water10ml.kg-1.d-1for6weeks).(2) Blood pressures were measured byTail-Cuff Method in the periods of pre-operation, after-operation for1stand7thweek respectively.(3)Measurement of left ventricle weight/bodyweight (g/100g):7weeks after operation, the rats wereweighted,anesthetized and removed the hearts immediately,and then thepulmonary artery, pulmonary vein, aorta, superior vena cava, inferiorvena cava were also taken away. The hearts were washed with precooledPBS(0.1mol.L-1,pH7.4),and dried with cleanly filter paper,then the leftventricles were separated by the mitral and ventricular septal levels.The left ventricular weight/body weight (g/100g) ratios were calculated.(4)The left ventricle pathology:the variations of myocardiumwere observed by the microscope after the myocardium was fixed in4%formalin and embedded in paraffin and HE staining.(5) Determinationof the calcineurin (CaN) activity: About100mg frozen myocardial wasprepared into homogenate, and then centrifuged at12000rpm for5minutes. Calcineurin (CaN) activity was determined by DeterminingPhosphorus Method.(6)Determination of the sarcoplasmic reticulumCa2+-ATPases(SERCA) activity: The myocardial homogenate was used todetermin the activity of SERCA by using Ca2+-ATPases kits.(7) ThemRNA levels of CaN were detected by RT-PCRmethod.Result:(1)Changes of rats blood pressure:the blood pressure ofSham group did not have significant changes in the periods of pre-andafter-operation,but the blood pressure of Contorl group and each treatedgroup increased obviously1st week after surgery(157.9±6.72vs103.2±8.28mmHg,P<0.05); the blood pressure of each treatedgroup(CP,TFH,Com) were lower in the7ththan1stweek.（135.8±4.94vs157.9±6.72mmHg,P<0.05）（,141.1±5.60vs157.9±6.72mmHg,P<0.05）,（119.5±6.69vs157.9±6.72mmHg,P<0.05）. Compared with Sham group,the blood pressure of Contorl group and every treated group increasedobviously in1stweek after surgery（157.9±6.72vs105.1±8.27mmHg,P<0.05）;compared with Control group, the blood pressure of each treatedgroup(CP,TFH,Com) decreased in the7thweek.（135.8±4.94vs168.3± 4.78mmHg,P<0.05）（,141.1±5.60vs168.3±4.78mmHg,P<0.05）（,119.5±6.69vs168.3±4.78mmHg,P<0.05）,the effect of blood pressure control inCom group was best (P<0.05),but there was insignificant differencebetween the CP group and TFH group(141.1±5.60vs135.8±4.94mmHg,P>0.05).(2)The left ventricle weight/body weight (g/100g)ratio:Compared with Sham group,the left ventricle weight/body weightratio of Control group increased significantly （0.24±0.0085vs0.18±0.0036， P<0.05）;compared with Control group, the left ventricleweight/body weight ratio of CP group,TFH group and Com groupdecreased（0.19±0.0054vs0.24±0.0085，P<0.05）、（0.20±0.0076vs0.24±0.0085，P<0.05）、（0.18±0.0043vs0.24±0.0085，P<0.05）,while the effectof Com group was the best（P<0.05）. The left ventricle weight/bodyweight ratio of CP group was lower than the TFH group’s（0.19±0.0054vs0.20±0.0076，P<0.05).(3)Myocardial pathology (×200times):Myocardial cells of Control group were disarranged and becamticker,and the intercellular spaces were extre-mely edematous,accompanied by branches and hyperchromatic nuclei,while, the cellswere normal in the Sham group.Compared with the Control group,thecells of each treatment group were smaller and arranged more orderly,butno significant differences between treatment groups could be obsreveedfrom the slices.(4)Determination of the CaN activity: Compared withSham group,the CaN activity of Control group increased significantly （0.66±0.10vs0.25±0.07U/mgprot，P<0.01）; compared with Controlgroup, the CaN activity of CP group,TFH group and Com groupdecreased （0.47±0.09vs0.66±0.10U/mgprot，P<0.01）,（0.49±0.08vs0.66±0.10U/mgprot，P<0.01）,（0.36±0.06vs0.66±0.10U/mgprot，P<0.01）,the effect of Com group was best(P<0.05),but it wasn’tsignificant that the difference between the CP group and TFHgroup(0.49±0.08vs0.47±0.09U/mgprot，P>0.05).(5) Determination ofthe SERCA activity:Compared with Sham group,the SERCA activity ofControl group was significantly lower（19.79±0.80vs27.1±0.63μmolPi/mgprot/hour，P<0.01）; compared with Control group, the SERCA activityof CP group,TFH group and Com group increased（24.90±0.79vs19.79±0.80μmolPi/mgprot/hour，P<0.01）,（24.32±0.70vs19.79±0.80μmolPi/mgprot/hour，P<0.01）,（25.43±0.67vs19.79±0.80μmolPi/mgprot/hour，P<0.01）; the SERCA activity of TFH group was lower than the Comgroup（24.32±0.70vs25.43±0.67μmolPi/mgprot/hour,P<0.01）,but therewas no significant difference between the CP group and TFHgroup(24.32±0.70vs24.90±0.79μmolPi/mgprot/hour, P>0.05), the CPgroup and Com group(24.90±0.79vs25.43±0.67μmolPi/mgprot/hour,P>0.05).(6)Expression of CaN-mRNA:the expression of CaN-mRNA ofControl group was higher than the Sham group（0.41±0.03vs0.08±0.01,P<0.01）; compared with Control group, the expression of CaN-mRNA ofCP group,TFH group and Com group decreased （0.27±0.02vs0.41±0.03, P<0.01）,（0.29±0.03vs0.41±0.03,P<0.01）,（0.12±0.01vs0.41±0.03,P<0.01）, the effect of Com group was best(P<0.05),but it wasn’t significantthat the difference between the CP group and TFH group(0.29±0.03vs0.27±0.02,P>0.05).Conclusion:TFH has significant efficiency tocontrol blood pressure and prevent cardiac hypertrophy due to theSERCA activity and CaN signal pathway.The cardiovascular protectiveeffect of TFH is equal to captopril,and the combination of both drugs hassynergistic work. |
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