Cardiovascular and hidroelectrolytic changes in rats fed with high-fat diet

• Published in: Behavioural brain research 2019-11, Vol.373, p.112075-112075, Article 112075
• Main Authors: Sá, Jéssica Matheus, Barbosa, Rafaela Moreira, Menani, José V., De Luca, Laurival Antônio, Colombari, Eduardo, Almeida Colombari, Débora Simões
• Format: Article
• Language: English
• Subjects: Angiotensin II; Arterial pressure; Obesity; Renal excretion; Water intake
• ISSN: 0166-4328; 1872-7549
• DOI: 10.1016/j.bbr.2019.112075

•ANG II-induced pressor, but not drinking response is potentiated in HFD-fed rats.•Daily and prandial water intake is reduced in HFD-fed rats.•Salivation in rats ingesting HFD may play a role in the reduced prandial and daily water intake.•The reduction in urinary volume is probably related to the decrease in water intake. Obesity activates the renin-angiotensin and sympathetic systems facilitating hypertension and changes in the hydroelectrolytic balance. In the present study, in rats fed with high-fat diet (HFD), we investigated daily water intake and urinary excretion, prandial consumption of water and the changes in blood pressure and water intake to intracerebroventricular (icv) angiotensin II (ANG II). Male Holtzman rats (290–320 g) were fed with standard diet (SD, 11% calories from fat) or HFD (45% calories from fat) for 6 weeks. Part of the animals received a stainless steel cannula in the lateral ventricle (LV) at the 6th week after the beginning of the diets and the experiments were performed at the 7th week. The pressor effect, but not the dipsogenic response to acute icv injection of ANG II, was potentiated in the HFD rats. Daily water intake and urinary volume were reduced in rats fed with HFD with no significant changes in sodium excretion. Prandial water consumption was also reduced in rats ingesting HFD, an effect almost totally reverted blocking salivation with atropine. These results show a potentiation of the pressor response to icv ANG II in HFD-fed rats, without changing icv ANG II-induced water intake. In addition, prandial and daily water intake and urinary volume were reduced in HFD-fed rats, without changing sodium excretion. Salivation in rats ingesting HFD may play a role in the reduced prandial and daily water intake.