What it is
Angiotensin is not one peptide but a family, all cut from the front end of a large blood protein, angiotensinogen (476 residues; UniProt P01019). The cuts happen in steps:
| Peptide | Sequence | Length | Precursor residues |
|---|---|---|---|
| Angiotensin I | DRVYIHPFHL | 10 | 25–34 |
| Angiotensin II | DRVYIHPF | 8 | 25–32 |
| Angiotensin 1–7 | DRVYIHP | 7 | 25–31 |
| Angiotensin III | RVYIHPF | 7 | 26–32 |
| Angiotensin IV | VYIHPF | 6 | 27–32 |
The enzyme renin releases angiotensin I; trimming two more amino acids gives angiotensin II, the main active hormone. That trimming enzyme, angiotensin-converting enzyme, is what the ACE-inhibitor blood-pressure drugs block. The research compound dihexa was designed from angiotensin IV.
What it does
UniProt's function annotation calls the system an essential regulator of blood pressure and of body fluid and electrolyte balance. Angiotensin II, acting through the receptors AGTR1 and AGTR2:
- constricts blood vessels directly;
- changes heart rate and contractility through the sympathetic nervous system;
- makes the adrenal cortex release aldosterone, which shifts how the kidneys keep salt and water.
Angiotensin 1–7 is annotated as working the other way, through a different receptor, MAS1, with vasodilator effects. Another short peptide that widens vessels, bradykinin, is broken down by the same converting enzyme — one reason the two systems are discussed together.
The approved infusion
Giapreza is synthetic human angiotensin II for intravenous infusion, approved on 2017-12-21 (NDA 209360; label 2026-07-22). Its one indication: to increase blood pressure in adults with septic or other distributive shock. A generic angiotensin II acetate was approved in 2025 (ANDA 216966).
The approval rested on ATHOS-3 (New England Journal of Medicine, 2017, PMID 28528561; funded by the manufacturer). Patients in vasodilatory shock already on high-dose vasopressors were randomised to angiotensin II or placebo:
| Outcome | Angiotensin II (n = 163) | Placebo (n = 158) |
|---|---|---|
| Blood-pressure response at hour 3 | 69.9% | 23.4% |
| Serious adverse events | 60.7% | 67.1% |
| Death by day 28 | 46% | 54% (P = 0.12) |
The blood-pressure result was clear; the difference in deaths was not statistically significant. The label's infusion starts at 20 ng/kg/min, adjusted as often as every five minutes.
Where it stands
Angiotensin II is an approved hospital medicine for one use (openFDA, 2026-10-04). PubMed returns 166,342 records for angiotensin, 7,885 tagged as randomised controlled trials — most of them about drugs that block the system rather than the peptides themselves.
Related reading
For the vasodilator peptide degraded by the same enzyme, see bradykinin. For another peptide hormone that raises blood pressure and is used in shock, see the antidiuretic hormone vasopressin, and for its kidney-acting relative used in liver disease, terlipressin.