Brief Report ACE2 activity is increased in monocyte-derived macrophages from prehypertensive subjects

Background. Hypertension is a major risk factor for cardiovascular disease and the renin– angiotensin–aldosterone system (RAAS) plays a central pathophysiological role in its formation. Angiotensin-converting enzyme (ACE) and its homo-logue ACE2 control the formation of counteracting effectors, angiotensin II (AngII), a potent vasopressor and Ang-(1–7) which has vasodilatory action. It is therefore hypothesized that the balance of the activities of these two enzymes, ACE and ACE2, could be important for the control of blood pressure (BP). Methods. Monocyte-derived macrophages were isolated from blood samples of normotensives (NT), prehypertensives (preHTN) and untreated hypertensive (HTN) male patients (n 28, 18 and 11, respectively). The activities of ACE2 were determined by measuring leucine or phenylalanine released following hydrolysis of Ang I and Ang II, respectively. The activity of ACE was measured using a synthetic substrate