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Central angiotensinergic inhibition modulates physical exercise‐induced cardiovascular adjustments in rats
Author(s) -
Leite Laura Hora Rios,
Santiago Henrique Pereira,
Lima Daniel Carvalho,
Pires Washington,
Coimbra Cândido Celso
Publication year - 2011
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.25.1_supplement.1056.8
Subject(s) - blood pressure , heart rate , losartan , medicine , blockade , cardiology , angiotensin ii receptor type 1 , endocrinology , pulsatile flow , renin–angiotensin system , receptor
To assess the effects of central AT 1 receptors blockade on cardiovascular adjustments during exercise, blood pressure and heart rate of Wistar rats were measured during running until fatigue after intracerebroventricular injection of losartan (Los) or saline (Sal) (n=6/group). Pulsatile arterial pressure was recorded by a catheter implanted into the left carotid artery, from which were derived mean blood pressure and heart rate measurements. Rats injected with Los had a higher mean blood pressure from 6 min of exercise until the fatigue point (136.8 ± 1.9 mmHg Los vs. 125.3 ± 3.0 mmHg Sal; P < 0.05). These rats also showed a more intense increase in heart rate seen after 7 min of exercise and sustained until fatigue (522.2 ± 21.5 bpm Los vs. 466.0 ± 21.0 bpm Sal; P < 0.05). In addition, the 24% reduction in exercise time shown by Los‐rats (13.0 ± 1.1 min Los vs. 16.8 ± 0.9 min Sal; P < 0.01) correlated negatively with the mean blood pressure at fatigue point (r = 0.68, P < 0.05). We conclude that the central angiotensinergic system is involved in the regulation of cardiovascular adjustments in exercising rats, since central AT 1 receptors blockade leads to increased blood pressure and heart rate, suggesting a higher sympathetic activation to exercise. Furthermore, the enhanced cardiovascular effort induced by central angiotensinergic blockade contributes to the reduction of exercise performance. Supported by: CNPq, FAPEMIG and CAPES.