Intra-arterial infusion of Angiotensin-(1-7) increased forearm blood flow similarly in normotensive subjects (28.7%) and hypertensive patients (31.8%) via a nitric oxide-independent pathway.
Does intra-arterial infusion of Angiotensin-(1-7) increase forearm blood flow in normotensive subjects and patients with essential hypertension?
Angiotensin-(1-7) acts as a vasodilator in the human forearm circulation through a nitric oxide-independent pathway, with preserved effects in essential hypertension.
Absolute Event Rate: 31.8% vs 28.7%
p-value: p=<0.05
Previous animal studies have shown that angiotensin (Ang)-(1-7) is a biologically active component of the renin-angiotensin system, acting as a vasoactive agent, and may play a role in the blood pressure regulation. There is little information, however, on the effect of Ang-(1-7) on human circulation or the mechanism of its action. To investigate the effect of Ang-(1-7) on forearm circulation and to determine whether this effect is altered in patients with essential hypertension, we measured change in forearm blood flow using venous occlusion plethysmography in response to intra-arterial infusion of Ang-(1-7) (10(-10), 10(-9), and 10(-8) mol/min; for 5 minutes) in normotensive control subjects (n=8) and patients with essential hypertension (n=8). Infusion of Ang-(1-7) significantly increased the forearm blood flow response in a dose-dependent manner in both normotensive control subjects (28.7+/-9.7%, at 10(-8) mol/min; P<0.05) and hypertensive patients (31.8+/-15.2%, at 10(-8) mol/min; P<0.05). The vasodilatory effect of Ang-(1-7) was similar in the two groups. Intra-arterial infusion of N(G)-monomethyl-L-arginine, a nitric oxide synthesis inhibitor, did not alter the forearm blood flow response to Ang-(1-7) in either group. These findings suggest that Ang-(1-7) causes vasodilation in forearm circulation of normotensive subjects and patients with essential hypertension through a pathway that is independent of nitric oxide synthesis.
Sasaki et al. (Sun,) conducted a other in Essential hypertension (n=16). Angiotensin-(1-7) vs. Normotensive controls was evaluated on Change in forearm blood flow (p=<0.05). Intra-arterial infusion of Angiotensin-(1-7) increased forearm blood flow similarly in normotensive subjects (28.7%) and hypertensive patients (31.8%) via a nitric oxide-independent pathway.