Review Article

Renin-Angiotensin System Inhibitors in COVID-19: Current Concepts

Figure 1

Roles of ACE (angiotensin-converting enzyme) and ACE-2 (angiotensin-converting enzyme-2) in the renin-angiotensin system. Renin cleaves angiotensinogen produced by the liver to angiotensin I which is further cleaved to angiotensin II by ACE enzyme. The primary function of the ACE-2 enzyme is to cleave angiotensin II to angiotensin (1–7) and angiotensin I to inactive angiotensin (1–9). The angiotensin II exerts its negative effects of vasoconstriction, proinflammation, and profibrosis through its interaction with the AT1R (angiotensin II type 1 receptor). In contrast, the angiotensin (1–7) exerts its beneficial effects of vasodilation, anti-inflammation, and antifibrosis through its interaction with MasR (Mas receptor).