Therapeutic potential of targeting the renin angiotensin system in portal hypertension

Figure 1 Overview of the renin angiotensin system. The effects of the renin angiotensin system (RAS) are determined by the balance between the angiotensin II (Ang II)-mediated “classical” axis, depicted in blue, which is vasoconstrictive and the angiotensin-(1-7) [Ang-(1-7)]-mediated “alternate” axis, depicted in orange, which is vasodilatory. Both Ang II and Ang-(1-7) can stimulate the Ang II type 2 (AT2) receptor, depicted in green; the effects of which are often analogous to those mediated by the Ang-(1-7) receptor Mas. Recent evidence indicates that a new member, Ang-(1-12), which is cleaved from angiotensinogen, also contributes either indirectly via Ang I or directly to the pool of Ang-(1-7). NEP: Neural endopeptidase; ACE: Angiotensin converting enzyme; ACE2: Angiotensin converting enzyme 2; AT1 receptor: Angiotensin II type 1 receptor.