Wang Louis W, Huttner Inken G, Santiago Celine F, Kesteven Scott H, Yu Ze-Yan, Feneley Michael P, Fatkin Diane
Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales 2010, Australia.
Faculty of Medicine, University of New South Wales, Kensington, New South Wales 2052, Australia.
Dis Model Mech. 2017 Jan 1;10(1):63-76. doi: 10.1242/dmm.026989. Epub 2016 Dec 20.
The zebrafish (Danio rerio) is an increasingly popular model organism in cardiovascular research. Major insights into cardiac developmental processes have been gained by studies of embryonic zebrafish. However, the utility of zebrafish for modeling adult-onset heart disease has been limited by a lack of robust methods for in vivo evaluation of cardiac function. We established a physiological protocol for underwater zebrafish echocardiography using high frequency ultrasound, and evaluated its reliability in detecting altered cardiac function in two disease models. Serial assessment of cardiac function was performed in wild-type zebrafish aged 3 to 12 months and the effects of anesthetic agents, age, sex and background strain were evaluated. There was a varying extent of bradycardia and ventricular contractile impairment with different anesthetic drugs and doses, with tricaine 0.75 mmol l having a relatively more favorable profile. When compared with males, female fish were larger and had more measurement variability. Although age-related increments in ventricular chamber size were greater in females than males, there were no sex differences when data were normalized to body size. Systolic ventricular function was similar in both sexes at all time points, but differences in diastolic function were evident from 6 months onwards. Wild-type fish of both sexes showed a reliance on atrial contraction for ventricular diastolic filling. Echocardiographic evaluation of adult zebrafish with diphtheria toxin-induced myocarditis or anemia-induced volume overload accurately identified ventricular dilation and altered contraction, with suites of B-mode, ventricular strain, pulsed-wave Doppler and tissue Doppler indices showing concordant changes indicative of myocardial hypocontractility or hypercontractility, respectively. Repeatability, intra-observer and inter-observer correlations for echocardiographic measurements were high. We demonstrate that high frequency echocardiography allows reliable in vivo cardiac assessment in adult zebrafish and make recommendations for optimizing data acquisition and analysis. This enabling technology reveals new insights into zebrafish cardiac physiology and provides an imaging platform for zebrafish-based translational research.
斑马鱼（Danio rerio）在心血管研究中日益成为一种受欢迎的模式生物。通过对斑马鱼胚胎的研究，人们对心脏发育过程有了重要的认识。然而，由于缺乏用于体内评估心脏功能的可靠方法，斑马鱼在模拟成人发病型心脏病方面的效用受到了限制。我们建立了一种使用高频超声进行水下斑马鱼超声心动图检查的生理方案，并在两种疾病模型中评估了其检测心脏功能改变的可靠性。对3至12个月大的野生型斑马鱼进行了心脏功能的系列评估，并评估了麻醉剂、年龄、性别和背景品系的影响。不同的麻醉药物和剂量会导致不同程度的心动过缓和心室收缩功能受损，0.75 mmol·l的三卡因具有相对更有利的特征。与雄性相比，雌性鱼体型更大，测量变异性也更大。尽管雌性心室腔大小随年龄的增加比雄性更大，但在将数据归一化至体型后没有性别差异。在所有时间点，两性的收缩期心室功能相似，但从6个月起舒张期功能的差异就很明显。两性的野生型鱼在心室舒张期充盈时都依赖心房收缩。对白喉毒素诱导的心肌炎或贫血诱导的容量超负荷的成年斑马鱼进行超声心动图评估，准确地识别出心室扩张和收缩改变，一系列B模式、心室应变、脉冲波多普勒和组织多普勒指标分别显示出一致的变化，表明心肌收缩力减弱或增强。超声心动图测量的重复性、观察者内和观察者间相关性都很高。我们证明高频超声心动图能够在成年斑马鱼中进行可靠的体内心脏评估，并为优化数据采集和分析提出建议。这项使能技术揭示了斑马鱼心脏生理学的新见解，并为基于斑马鱼的转化研究提供了一个成像平台。
