Establishment of mouse model of transverse aortic constriction in a minimally invasive way and echocardiographic assessment / 中华胸心血管外科杂志

ABSTRACT

Objective To explore the feasibility of establishing a modified mouse model of pressure overload induced left ventricular hypertrophy by transverse aortic constriction(TAC).Methods 55 C57BL/6 female mice were randomly divided into three groups:severe TAC group (n =27),moderate TAC group (n =7) and sham surgery group (n =21),respectively.By ligating the aorta arch between innominate artery and the left common carotid artery with modified techniques in a minimally invasive way,moderate or severe aortic constriction were established successfully and reliably to mimic left ventricular(LV)outflow obstruction; to correctly evaluate the cardiac structural and functional responses to aortic arch banding,2-dimention (2D) and M mode transthoracic echocardiography (TTE) were deployed to monitor the LV contractile function and assess the LV hypertrophic changes induced by pressure overload at 4 weeks after the surgery.Results The mouse model of aortic constriction was established successfully with a post-operative survival rate more than 88％.And all these operated mice were able to survive at least 4 weeks long.Eccentric left ventricular hypertrophic changes were detected with echocardiographic measurement 4 weeks after the banding operation in both mTAC and sTAC group,as dilated left ventricular lumen with enlarged LV end-diastolic dimension (LVEDD) and LV end systolic-dimension (LVESD) were confirmed.Mice with moderate banded aorta exhibited a compensated LV hypertrophy with preserved contractile functions and satisfactory ventricular wall movements to some extent,although left ventricular fractional shorting (LVFS) reduced gradually from 0.403 ± 0.007 to 0.340 ± 0.015 (P＜0.05) ; while in severe banded (sTAC) mice,LVFS reduced more significantly as a sharp decrease from 0.438 ± 0.011 to 0.216 ± 0.012 (P ＜ 0.01) were detected,combined with poor contractile function and stiff ventricular wall movements,exhibiting a de-compensated pathological left ventricular hypertrophy.Conclusion This modified TAC opcration could be easily carried out,and the TAC mouse model mentioned in the present research was an effective pressure overload model with several superiorities including less trauma,improved post-operative survival rate,rapid recovery and satisfactory reproducibility,thus a better and recommended mouse model for specific research purpose concerning LV hypertrophy mechanistic studies.