超声背向散射积分评价缬沙坦药物治疗对自发性高血压大鼠心肌组织纤维化的逆转作用

Application of Ultrasonic Integrated Backscatter Technique in the Evaluation of the Regression of Myocardial Fibrosis in the Spontaneously Hypertensive Rats after Valsartan Therapy

目的:应用心肌超声背向散射积分技术(IBS)评价缬沙坦药物治疗对自发性高血压大鼠(SHR)心肌组织纤维化的逆转作用。方法:选用24周WKY大鼠7只(W24组);SHR 21只,其中14只作为对照组分别于14周(SHR-C14组)、24周(SHR-C24组)进行检测,另7只14周SHR大鼠每天予以缬沙坦30mg/kg灌胃,持续至第24周(SHR-T24组)。测量各组大鼠的尾动脉收缩压;采用Bergman氏法测定各组大鼠的心肌组织内羟脯氨酸浓度(HC);应用传统超声测量各组大鼠室间隔及左室后壁厚度及左室短轴缩短率(FS);应用超声背向散射积分技术获取各组大鼠室间隔基底部心肌组织的心肌超声背向散射积分(IBS)变化曲线图。结果:缬沙坦药物治疗可以有效地控制及降低SHR的收缩压(SHR-T24 vs SHR-C14,P<0.01;SHR-T24 vs SHR-C24,P<0.01)、心肌内羟脯氨酸浓度(SHR-T24 vs SHR-C14,P<0.05;SHR-T24 vs SHR-C24,P<0.01)以及其室间隔心肌超声背向散射积分平均值(AII)(SHR-T24 vs SHR-C14,P<0.05;SHR-T24 vs SHR-C24,P<0.01);能提高左室FS(SHR-T24 vs SHR-C14,P<0.05;SHR-T24 vs SHR-C24,P<0.01)室间隔IBS随心动周期变化幅度(CVIB)(SHR-T24 vs SHR-C14,P<0.01;SHR-T24 vs SHR-C24,P<0.01);SHR大鼠在治疗前后及其对照组中,其室间隔心肌AII与HC之间存在良好的相关性(r=0.78,P<0.001)。其室间隔CVIB与FS之间也存在较好的相关性(r=0.72,P<0.001)。结论:缬沙坦药物治疗可以对高血病心肌纤维化起逆转作用并同时改善心肌收缩功能。治疗前后,通过监测IBS可以观察其心肌组织纤维化的逆转程度;通过监测CVIB可以反映其心肌收缩功能的改变。

Objective：Using ultrasonic integrated backscatter （IBS） technique to evaluate the regression of myocardial fibrosis in the spontaneously hypertensive rats （SHRs） after Valsartan therapy. Methods： The study included 24-week-old WKY rats （n=7,W24）, 14-week-old SHRs （n= 7 ,SHR-C14） and 24-week-old SHRs （n= 7 ,SHR-C24） which were used as control group,and 14-week-old SHRs （n= 7） which were fed with Valsartan （30mg/kg/d） by gastrogavage for 10 weeks （SHR-T24） as treatment group. The systolic pressure of the tail artery of all groups was measured. The concentration of myocardial hydroproline （HC） was measured by the Bergman＇s technique. The thickness of inter-ventricular septum, posterior wall of left ventricle as well as the fraction shortening （FS） of left ventricle were assessed with conventional ultrasonography. The curves of ultrasonic myocardial integrated backscatter score （IBS） of the basal septum were acquired in several cardiac cycles. Results： After Valsartan therapy, the systolic pressure of the SHR-T24 group, the concentration of myocardial HC and the average image intensity （AII） of the myocardial IBS were decreased and effectively under controlled, showing as （SHR-T24 vs SHR-C14,P〈0.01 ） ; SHR-T24 vs SHR-C24, P〈 0.01 ） ; （SHR-T24 vs SHR-C14, P〈 0. 05 ; SHR-T24 vs SHR-C24, P〈0.01 ） ;SHR-T24 vs SHR-C14, P〈0.05 ;SHR-T24 vs SHR-C24 ,P〈0. 01）, respectively. The FS of left ventricle,and the myocardial cyclic variation in IBS （CVIB） were improved, showing as （SHR-T24 vs SHR-C24, P〈0.05; SHR-T24 vs SHR-C24 P 〈 0.01 ） （ SHR-T24 vs SHR-C14, P 〈 0.01 ; SHR-T24 vs SHR-C24, P 〈 0.01 ） respectively. A strong correlation was found between the all and the myocardial HC （r=0.78,P〈0.001） as well as between the CVIB and the FS （r=0.72,P〈0. 001） in the after treatment group vs control groups of SHRs. Conclusion：Of the SHRs after Valsartan therapy,myocardial fibrosis could be regressed;the FS could be improved. The regression of myocardial fibrosis could be monitored by the IBS and the improvement of contracture function of myocardium could be demonstrated by CVIB.