Chronic Treatment with an orally active formulation of Angiotensin‐(1‐7) improves autonomic control in SHR

Abstract

Angiotensin‐(1–7) (ANG‐(1‐7)) seems to have an important role in cardiovascular regulation. In hypertension, autonomic control and ANG(1‐7) are altered. Heart rate (HRV) and blood pressure variability (BPV) are important predictors of cardiovascular risk and provide information about cardiac and vascular autonomic modulation. In this work we investigated the effect of chronic treatment with orally active formulation of (HPâCD/Ang‐(1‐7)) on autonomic modulation in spontaneously hypertensive rats (SHR). Treated group (AG, n=8) received, equivalent to 30 ug/Kg Ang‐(1‐7), by gavage once a day for 10 weeks. The control group (CG, n=8) received tap water. Blood pressure was recorded and stationary sequences of 250 beats were randomly chosen. Frequency domain analysis of HRV and BPV was performed with an autoregressive model. Systolic blood pressure, as well as BPV and vascular sympathetic modulation, were reduced after treatment. With respect to cardiac autonomic modulation, although the treatment did not cause a reduction in HR, ANG(1‐7) caused an increase in HRV, showing an improvement in the cardiac autonomic control. The sympathetic‐vagal balance was reduced in the CG. Our results show that the oral treatment with ANG(1‐7) was able to improve relevant cardiovascular parameters which are altered in hypertension, suggesting the possibility of a novel pharmacological intervention in hypertension therapy.