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Sympathetic hyperactivity and AT1 receptor overexpression are associated with high‐fat diet‐induced hypertension in young rats
Author(s) -
Americo Anna Laura,
Muller Cynthia,
Evangelista Fabiana,
Farah Vera,
Fiorino Patricia
Publication year - 2015
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.29.1_supplement.964.3
Subject(s) - medicine , endocrinology , angiotensin ii receptor type 1 , basal (medicine) , receptor , blood pressure , ventricle , renin–angiotensin system , angiotensin receptor , chemistry , diabetes mellitus
We evaluated the autonomic nervous system (ANS) and components of the renin angiotensin system (RAS) AT1 and MAS receptors in the control of blood pressure (BP) in young rats. Male Wistar rats (n=8/group) were fed during 8 weeks with control diet (C) or high‐fat diet (HF, 30% lipids) since the weaning. The animals were catheterized to record basal BP and heart rate (HR) during 15 minutes. The ANS was evaluated by spectral analysis (SA) in the time and frequency domain. At the end of the protocol, the animals were killed by overload of anesthetic (Ketamine/Xylazine, ip.) and the heart was harvested for left ventricle (LV) isolation. The AT1 and MAS receptors in the LV were performed by Western Blot. The HF group showed increase in the basal BP (12%) and HR (6%).In the SA, systolic BP (10%) and low frequency band were higher in HF group compared with C group as revealed by the increase in the variability of pulse interval (C: 9± 1 vs. HF: 15 ± 2 Hz) and in the variability of systolic BP (C: 34 ± 2 vs. HF: 42 ± 3 Hz). No difference was observed in the high frequency band between groups.The AT1 receptor protein expression was higher in the HF group (52%) compared with C group, however the increase in MAS receptor expression (18%) in the HF group was not significantly different from C group. In conclusion, the results suggest that the sympathetic hyperactivity and the overexpression of AT1 receptor could be involved in the genesis of the hypertension observed in young rats fed a high‐fat diet. Supported by Mackpesquisa.