PP.28.07

Abstract

Objective: We have reported that angiotensinogen gene expression was increased in the hypertrophic hearts of salt-sensitive hypertensive (SSH) rats. The methylated status of the promoter region of angiotensinogen gene influences its gene expression. In order to clarify the relationships between the methylation status of angiotensinogen gene and high salt diet, we examined the three parts of CpG islands of angiotensinogen gene in the hearts of SSH rats. Design and method: Five male SSH rats were fed with high salt diet (8% NaCl) or normal salt diet (0.45%) for 8 weeks. Plasma aldosterone and PRA were measured at 8 weeks. The DNA and RNA were extracted from the hearts of each experimental group. Histological analysis of the hearts was done. The methylation status was estimated by bisulfite sequencing. The expression levels of mRNA of angiotensinogen were measured by quantitative real time PCR. Results: High salt diet significantly increased blood pressure and heart weight compared with normal salt diet (p < 0.05). Plasma aldosterone and PRA were decreased. The mRNA levels of angiotensinogen in the hearts were significantly increased (p < 0.05) in the high-salt diet group. Hypomethylated status of the angiotensinogen gene was seen in the hearts of SSH rats fed with high salt diet. Conclusions: Epigenetic influence of high salt diet may affect gene expression of angiotensinogen and partly induced hypertrophy of the hearts of SSH rats.