Cardiovascular & General; Cardiovascular & Metabolic

Bradykinin

Bradykinin is what inflammation feels like, in molecular form. Released where tissue is injured, it widens blood vessels, loosens the junctions between the cells lining them so fluid leaks into the tissue, and fires pain nerves directly — the redness, the swelling and the ache, each traceable to one nine-amino-acid peptide. It also explains one of medicine's stranger side effects: angiotensin-converting enzyme (ACE) inhibitors slow the enzyme that clears bradykinin away, which is why a blood pressure tablet can swell a person's face and airway shut. Every medicine on file built around it, icatibant and ecallantide, is designed to block it rather than supply it, and in research it is infused into the forearm as a standard test of how well vessels dilate.

Last updated 12 August 2026

Studied forVasodilation research · Vascular permeability research · Inflammatory pain context

Evidence on file5 human observational studies · 1 human case report or series · 1 animal study · 1 in-vitro study · 1 citation not yet graded

Strongest sourceIcatibant for acute hereditary angioedema attacks in pediatric patients: A systematized review. (human observational study)

Mechanism

Activates the B2 receptor on endothelium and nociceptors, raising nitric oxide and prostaglandins and loosening endothelial junctions.

Reported effects

What sources associate with this compound. Reported categories, not outcomes we have graded — each would need its own citation and rung.

Vasodilation research
Vascular permeability research
Inflammatory pain context

Dosing on file unverified

IV bolus: ~0.1 µg/kg threshold; IV infusion: 0.125-1.25 µg/kg/min; 10-100 pmol/min; IV bolus: 0.001-7.5 µg/kg; Bolus: 60-600 pmol; Infusion: 30-2500 pmol/min

Carried from a source that labels it unverified, and reproduced with that label attached. A record of what is reported, not a recommendation. No citation on this page establishes it.

Literature on file 10

human observational
Icatibant for acute hereditary angioedema attacks in pediatric patients: A systematized review. graded on: a synthesis of human studies — the indexed publication type — “Systematic Review”
review or editorial
Therapeutic Targeting of the Bradykinin B2 Receptor in Immunological and Vascular Diseases: Insights from Kinin Biology to Clinical Outcomes. graded on: indexed as "Review" - secondary literature, not a study — “Review”
in vitro
G protein signaling capabilities at the bradykinin 2 receptor. graded on: an in-vitro system — read from the indexed abstract — “in vitro”
animal in vivo
Expression of PGE2, Histamine, Bradykinin, NaV-1.7, NaV-1.8, NaV-1.9 in Nerve Cells of Normal and Inflamed Dental Pulp Tissue Following Pulp Extirpation. graded on: an animal model — read from the indexed abstract — “rats”
human case series
Pediatric Non-Hereditary, Non-Allergic, Bradykinin-Mediated Angioedema in a Postoperative Intensive Care Patient: A Case Report. graded on: a case report or series — “Case Report”
human observational
NCT00685945: Renin-Angiotensin Aldosterone System and Fibrinolysis(RAAS) Interaction in Humans- Specific Aim 3 graded on: a registered clinical study — “clinicaltrials.gov”
human observational
NCT01413542: Pharmacogenetics of Ace Inhibitor-Associated Angioedema:Aim 1 graded on: a registered clinical study — “clinicaltrials.gov”
human observational
NCT02189122: Comparative Effects of Rapid-Release Aspirin and NHP-544C on Basal and Bradykinin Stimulated Prostacyclin Production graded on: a registered clinical study — “clinicaltrials.gov”
human observational
NCT03738878: Mechanism(s) Underlying Hypotensive Response to ARB/NEP Inhibition - Aim 1 graded on: a registered clinical study — “clinicaltrials.gov”

Not graded

1 citation whose study design could not be read from the title. Left ungraded rather than guessed at.

not graded
NCT01036659: Evaluation of Ecallantide for Acute Treatment of Angiotensin Converting Enzyme Inhibitor Induced Angioedema graded on: NCT01036659 is unknown and has posted no results - a registration, not a reported outcome — “NCT01036659”

Identity

Space-filling 3D model of Bradykinin, carbon grey, nitrogen blue, oxygen red — Built from the SMILES on this record — the atoms and bonds are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation, and where the SMILES leaves a stereocentre undefined the pose commits to one arbitrarily. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

2D chemical structure of Bradykinin — Built from the SMILES on this record — the atoms and bonds are exact. The shape is **one computed low-energy pose**, not a measured structure: a flexible peptide in solution has no single conformation, and where the SMILES leaves a stereocentre undefined the pose commits to one arbitrarily. The skeletal formula below claims connectivity and nothing more, which is what we actually know.

Molecular weight: 1060.2
Molecular formula: C50H73N15O11
CAS number: 58-82-2
PubChem CID: 439201 (Bradykinin)
UniProt: P01042 (precursor)
InChI key: QXZGBUJJYSLZLT-FDISYFBBSA-N
SMILES: C1C[C@H](N(C1)C(=O)[C@@H]2CCCN2C(=O)[C@H](CCCN=C(N)N)N)C(=O)NCC(=O)N[C@@H](CC3=CC=CC=C3)C(=O)N[C@@H](CO)C(=O)N4CCC[C@H]4C(=O)N[C@@H](CC5=CC=CC=C5)C(=O)N[C@@H](CCCN=C(N)N)C(=O)O
InChI: InChI=1S/C50H73N15O11/c51-32(16-7-21-56-49(52)53)45(72)65-25-11-20-39(65)47(74)64-24-9-18-37(64)43(70)58-28-40(67)59-34(26-30-12-3-1-4-13-30)41(68)62-36(29-66)46(73)63-23-10-19-38(63)44(71)61-35(27-31-14-5-2-6-15-31)42(69)60-33(48(75)76)17-8-22-57-50(54)55/h1-6,12-15,32-39,66H,7-11,16-29,51H2,(H,58,70)(H,59,67)(H,60,69)(H,61,71)(H,62,68)(H,75,76)(H4,52,53,56)(H4,54,55,57)/t32-,33-,34-,35-,36-,37-,38-,39-/m0/s1

Also called

Bradykinin (Cardiovascular)

Notes unverified prose

Human studies; dose-dependent vasodilation; Human IV/IA studies

Not on file 2

1 of the 8 fields we track hold nothing on this record, and each says why. 1 further absence is named below. A blank field is a bug; a named absence is a finding.

amino-acid sequencenothing we hold supplies it
half-lifenothing we hold supplies it

Each field links to every other record missing the same thing. The full ledger holds 765 gaps across 163 records.

At a glance

Strongest rung: human observational
Citations: 10
Regulatory: Human research reported (unverified)
Route: Intravenous / Intra-arterial
Declared gaps: 2

Citations by rung

Strongest wins, never an average.