Ageing and Blood Pressure Regulation: Dose‐response Relationships for Angiotensin, Blood Pressure, Atrial Natriuretic Peptide and Aldosterone in Normal Subjects of Varying Ages

Abstract

1. Infusion of increasing doses of angiotensin II (AII) in normal subjects sequentially increased blood pressure, aldosterone and atrial natriuretic peptide (ANP) levels. 2. The slope of ANP response to AII was positively correlated with basal ANP and with the slope of blood pressure response to AII (pressor slope) but not with age. 3. This is consistent with the response of ANP to AII being mediated partly by the rise in blood pressure, independent of ageing. 4. As expected in a selected normotensive population, there was no correlation between basal blood pressure and age, but pressor slope was positively correlated with age. 5. Thus, dose-response relationships may be an index of age-induced alterations in pressure regulatory mechanisms.

Angiotensin II enhances β-adrenergic receptor-mediated vasorelaxation in aortas from young but not old rats

“…Some investigators (4) have shown decreased vascular responsiveness with increasing age. Conversely, others (13) have shown an increased contractile effect to ANG II with increasing age. Still others (3) have reported no differences across age to the constrictor effect of ANG II.…”