Adult cardiovascular dysfunction induced by peri-pubertal high-fat diet exposure is mediated by the renin-angiotensin axis in male rats

This study investigated whether the renin-angiotensin system (RAS) is associated with the hypertension and metabolic syndrome induced by high-fat diet exposure during the peri-pubertal phase in rats. At postnatal day (PN) 30, male Wistar rats were randomly selected to be fed a normal diet (NF, 4.5% of fat) until PN 120 or a high-fat diet (HF, 35% lard) until PN 60 and then fed with a normal diet until PN 120. At PN 120, the function of the cardiovascular and RAS was assessed (5-16 animals per group). Statistical analyses were performed with the Student's T-test or 2-way ANOVA. HF rats showed increased arterial pressure (+ 9%, P = .004). The HF animals showed an increased pressor response at the lower (50 ng/kg/iv; + 50%, P = .048) and higher (300 ng/kg/iv; + 32%, P = .033) dose of Angiotensin II (Ang II), compared with NF animals. A higher depressor response to enalapril (5 mg/kg/iv; -100%, P = .014) was observed in HF rats. Greater endogenous circulating Ang II (+ 16%, P = .010) and lower endogenous circulating Ang (1-7) (-28%, P = .005) were observed in HF animals. The Ang II type 1 receptor (AT1R) mRNA expression increased (+ 81%, P = .037) in the heart of HF animals; however, Ang II type 2 receptor (AT2R; -91%, P = .039) and MAS receptor (MASR; -67%, P = .022) mRNA expression were reduced. In the aorta, AT1R mRNA expression increased (+ 124%, P = .046) in HF animals, whereas MASR mRNA expression decreased (-70%, P = .035), compared with NF animals. RAS is disrupted in adult hypertensive rats exposed to an HF diet during peri-pubertal life.