Premium
Anti‐hypertensive effect of chronic ICV angiotensin‐(1–7) in (mRen2)27 transgenic rats is blocked by Mas antagonist.
Author(s) -
Kangussu Lucas Miranda,
Santos Robson A.S.,
CampagnoleSantos Maria Jose
Publication year - 2013
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.27.1_supplement.1165.14
Subject(s) - medicine , endocrinology , renin–angiotensin system , antagonist , angiotensin ii , blood pressure , atrial natriuretic peptide , angiotensin ii receptor type 1 , ventricle , receptor
Overactivity of the renin‐angiotensin system, mainly through Ang II/AT1 axis, is critical in the pathogenesis of cardiovascular diseases. Ang‐(1–7)/Mas axis at the central nervous system may exerts a counter‐regulatory role in hypertension. In this study, Sprague Dawley (SD) and transgenic hypertensive rats (mRen2)27 (TG), instrumented with telemetry probes for arterial pressure (AP) measurements were subjected to 14 days of lateral ventricle (ICV) infusion of Ang‐(1–7) (200 ng/h) or Ang‐(1–7) associated with Mas receptor antagonist (A779, 1mg/h) or saline (0.5 ml/hour) through osmotic mini‐pumps. Ang‐(1–7) ICV attenuated hypertension of TG rats (144±8 mmHg vs 174±3 mmHg, before) similarly during the day and night. The fall in AP was accompanied by a decrease in heart rate only during the day (348±5 beats/min vs 367±6 beats/min). The AP levels were still higher than those of SD rats (102±2 mmHg). Ang‐(1–7) anti‐hypertensive effect was completely blocked by A779 (174±12 mmHg). The increased levels of atrial natriuretic peptide and brain natriuretic peptide in the heart of TG rats were significantly reduced by Ang‐(1–7) infusion and reversed by the concomitant infusion of Ang‐(1–7) and Mas receptor antagonist. These data indicate that the anti‐hypertensive effect induced by chronic increase in Ang‐(1–7) in the brain of (mRen2)27 rats is mediated by Mas receptor.