目的观察龙胆苦苷(GPS)对主动脉弓缩窄术诱导的C57BL小鼠心肌肥厚是否有预防作用。方法 40只雄性C57BL小鼠随机分成假手术组(n=8)和心肌肥厚模型组(n=32),心肌肥厚模型组通过主动脉弓缩窄术建立心肌肥厚模型。术后24 h随机分成心肌肥厚模型组和龙胆苦苷低[2.5 mg/(kg·d)]、中[5.0 mg/(kg·d)]、高[10.0 mg/(kg·d)]剂量组,分别给予生理盐水和不同剂量的龙胆苦苷处理4周。4周后进行心脏超声检查,并测量心脏重量/体重(HW/BW)、心脏重量/胫骨长度(HW/TL)、左心室舒张期末内径(LVEDD)、左心室收缩期末内径(LVESD)、左心室射血分数(LVEF)和短轴缩短率(FS)。PCR技术检测心肌组织中心房钠尿肽(ANP)、脑钠尿肽(BNP)、β肌球蛋白重链(β-MHC)表达的水平,并行病理学检查。结果与心肌肥厚模型组相比,龙胆苦苷[当剂量达到10.0 mg/(kg·d)]干预4周后,LVEDD较之下降24.9%,LVESD较之下降26.3%;LVEF较之升高49.5%,FS较之升高62.6%,差异均有统计学意义。初步证实龙胆苦苷能够显著降低心肌肥厚参数(心脏重量/体重)(P〈0.01),显著降低心肌细胞平均横截面积(P〈0.01)。与心肌肥厚模型组相比,龙胆苦苷组ANP、BNP和β-MHC的表达水平显著降低(P〈0.05)。结论龙胆苦苷对压力超负荷等诱导的心肌肥厚有保护作用。
Aim To investigate the protective effect of pretreatment with Gentiopicroside on transverse aortic constriction( TAC)-induced myocardial hypertrophy. Methods 40 male C57 BL mice were randomly divided into two groups: sham group( n = 6) and myocardial hypertrophy model group( n = 32). Mice in myocardial hypertrophy group were operated transverse aortic constriction. 24 h later,the mice in myocardial hypertrophy group were randomly divided into 4 groups: myocardial hypertrophy model group,Gentiopicroside high,middle and low dose group,which were given physiological saline and different doses of Gentiopicroside for 4 weeks. Echocardiogram was performed to assess the cardiac function changes. Heart weight to body weight ratio( HW / BW),heart weight / tibial length( HW / TL),left ventricular end-diastolic diameter( LVEDD),left ventricular end-systolic diameter( LVESD),left ventricular ejection fraction( LVEF)and left ventricular fractional shortening( FS) were measured. The expression levels of atrial natriuretic peptide( ANP),brain natriuretic peptide( BNP),and β-myosin heavy chain( β-MHC) in heart tissues and the size of cardiomyocytes were also observed. Results Compared with myocardial hypertrophy model group,the LVEDD decreased 24. 9% in Gentiopicroside group( especially dose up to 10. 0 mg /( kg · d),the LVESD decreased 26. 3%; while the LVEF increased49. 5%,the FS increased 62. 6%,respectively( P 〈 0. 01). The HW / BW and the cardiac myocyte cross-sectional area showed a decrease in Gentiopicroside group compared with myocardial hypertrophy model group( P 〈 0. 01),while still increased significantly compared with the normal control group. The expression of ANP,BNP and β-MHC in Gentiopicroside group were lower than those in myocardial hypertrophy model group( P 〈 0. 05). Conclusion Gentiopicroside can intervene the progress of pressure overload-induced myocardial hypertrophy in C57 BL mice.