The renin angiotensin system (RAS) is an important regulatory system for maintaining blood pressure, water and electrolyte balance, and cardiovascular homeostasis. Angiotensinogen is metabolized by renin to produce angiotensin I (AngI). Then AngI can be converted to angiotensin II (AngII) under the action of angiotensin-converting enzyme (ACE). It has been found that AngII is not the only biologically active molecule in angiotensin metabolites. Except for the well-known AngI (Ang1-10), AngII (Ang1-8), AngIII (Ang2-8) and AngIV (Ang3-8), there are many degradation products of angiotensin in the body, such as Ang1-9, Ang1-7, Ang1-5, etc.