Sprague-Dawley Rats Induced by Uninephrectomy, DOCA Injection, and Sodium Chloride: A Suitable Model for Chronic Hypertension with Cardiac Hypertrophy

Abstract

One of the most commonly used hypertensive rat models is the deoxycorticosterone acetate (DOCA)-salt hypertensive model. However, there is limited research on whether this model can induce cardiac hypertrophy. This study aimed to provide a reliable animal model for chronic hypertension that triggers cardiac hypertrophy using an echocardiographic approach to detect changes in cardiac performance. Twenty male Sprague-Dawley rats were randomly assigned to normal and DOCA-salt groups. Induction of chronic hypertension with cardiac hypertrophy was carried out by uninephrectomy, DOCA (20mg/kg/b.w) dissolved in 0.1mL of dimethylformamide (DMF) subcutaneously twice weekly and 1% NaCl in drinking water daily for five weeks. Blood pressure (BP) and echocardiography were observed. Serum was taken and checked for CK-MB and LDH. qRT-PCR determined the mRNA expression of B-type natriuretic peptide (BNP). Furthermore, we examined the histopathological characteristics of cardiac tissue. In the DOCA-salt model, BP were significantly increased, echocardiography showed that left ventricular end-diastolic posterior wall thickness (LVPWd), interventricular septal end-diastole thickness (IVSd) was significantly increased (P<0.01, respectively) and also exhibited decreased left ventricular internal diameter end-diastole (LVIDd). There was a significant increase in CK-MB, LDH activity, and mRNA expression of BNP in DOCA-salt group. Additionally, histopathological changes in cardiomyocyte cross-sectional area indicate cellular hypertrophy of the heart upon DOCA-salt administration. The findings showed that uninephrectomy with subcutaneous injection of DOCA dissolved in 0.1mL DMF followed by administration of 1% NaCl in drinking water could be a reliable animal model for chronic hypertension that triggers cardiac hypertrophy.