FIGURE 1.

The implications of angiotensin converting enzyme (ACE)2 dysfunction during severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. In the absence of infection, ACE2 is working at capacity and the levels of angiotensin II (ang II) are tightly regulated by conversion to angiotensin 1–7 (ang 1–7). Ang 1–7 activates the Mas receptor to regulate inflammation and vasomotor tone. During SARS-CoV-2 infection, ACE2 activity is reduced due to receptor occupancy, shedding and internalisation and the levels of ang II increase. Ang II activates the AT1 receptor to cause increased pro-inflammatory cytokine production, increased vasoconstriction, increased vascular permeability, oedema and lung injury. Pulmonary inflammation increases and acute severe respiratory failure may ensue.