Figure 1.

The classical and beneficial arms of RAS. Angiotensinogen is produced by the liver, then hydrolyzed by renin to form angiotensin I (AngI). Next, Ang I is hydrolyzed by angiotensin-converting enzyme (ACE) to produce the octapeptide angiotensin II (AngII). AngII can stimulate two receptors, AngII type 1 receptor (AT1) and AngII type 2 receptor (AT2). ACE2 catalyzes Ang II to generate the heptapeptide angiotensin-(1-7) (Ang-(1-7)), which can also be a product of ACE activity cleaving angiotensin-(1-9) (Ang-(1-9)). Ang (1-7) counteracts the effects of AngII by interacting with the receptors Mas (Mas) and/or MrgD.