【Animal modeling】-Isoproterenol-induced myocardial hypertrophy model rats based on implantable osmotic pump to improve and evaluate the conditions

  Objective Cardiac hypertrophy is a slowly developing and effective compensatory function, an adaptive response to hemodynamic or myocardial injury, and an independent risk factor for heart failure. It has been reported that in the rat model of myocardial hypertrophy induced by isoproterenol, the route of administration and the induction dose are very different, and the development process of the pathological phenotype of the model animals is not uniform.

  Methods Taking into account factors such as the advancement of previous methods, the homogeneity of model phenotype, the stability of the method, and the difficulty of replication, in this paper, the method of subcutaneously implanted osmotic pump was used to give ISO (4 mg / kg) at a low dose for a long time. , lasted for 28 d) induced the establishment of a rat model of myocardial hypertrophy, and the phenotype of the model was evaluated by ultrasound imaging, histopathological staining, immunofluorescence staining and Real-time PCR.

  Results The pathological phenotype of the model rats was typical. Global phenotype, including enlarged heart volume, ventricular wall thickness, and cardiac mass index; cellular phenotype, including enlarged cardiomyocytes, severe myocardial fibrosis, myocardial fiber fragmentation, dissolution, disappearance of mitochondrial ridges, vacuolization, myocardial fibrosis Z-line, M-line and blurred intercalated disc, etc. Molecular phenotype, including cardiac hypertrophy markers atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were significantly increased.

  Conclusion The rat model of myocardial hypertrophy established in this paper is stable and easy to replicate, with typical phenotypic characteristics, and is more suitable for scientific research such as gene function analysis and related drug screening.