EXPRESSION OF COMPONENTS OF THE RENIN‐ANGIOTENSIN SYSTEM IN THE BRAIN OF 2K1C HYPERTENSIVE RATS AFTER EXERCISE TRAINING

Abstract

The renin‐angiotensin system (RAS) modulates the activity of cardiovascular related areas in the brain and may be involved in the improvement of the autonomic function that can be induced by exercise training (ET) in hypertensive rats (HR). In this study, we evaluated mRNA expression of angiotensin receptors, AT1 and MAS, and the enzymes, ACE and ACE2, in the hypothalamus (Hy), ventrolateral medulla (VLM) and cortex (Co) of Goldblatt 2K1C HR submitted to ET (swimming, 60min/day, 5 days/week, for 4 weeks). Systolic arterial pressure (SAP, tail pletismography) was higher in 2K1C (158±6 mmHg; n=6) than in 2K1C‐ET rats (141±4 mmHg; n=6). The SAP of both groups were higher than SHAM (121±4; n=5). 2K1C rats showed increased expression of ACE and ACE2 in the Hy and an increased expression of AT1 in the Hy and VLM in comparison to SHAM. MAS expression was not different in Hy or VLM of 2K1C. ET induced an increase in the expression of ACE2 (3.6±0.4 u.a.; n=4 vs 0.72±0.12 u.a., n=4 in 2K1C) and Mas (3.2±0.4 u.a., n=4 vs 0.6±0.1 u.a., n=4 in 2K1C) and a decrease in AT1 (1.61±0.2 u.a. vs 2.50±0.46 u.a. in 2K1C) in the Hy. However, the expression of ACE, ACE2, Mas and AT1 was not changed in the VLM. No alteration in any of the components was observed in the Co of 2K1C or 2K1C‐ET rats. These data show that ET may induce selective changes in the brain RAS of hypertensive rats favoring the ACE2/MAS axis in the hypothalamus.