Page data last changed: . Chemistry registry snapshot: . Registry refreshes and identity assessments are separate from scientific content review.
A nine-residue kinin that dilates vessels, raises permeability and signals pain during inflammation.
Also known as: BK · kallidin-related kinin
Part of the Foundational & therapeutic peptides cluster
Overview
Bradykinin is a nine-amino-acid signaling peptide of the kinin group, released from kininogen by kallikrein. Acting through B2 and B1 receptors, it drives vasodilation, increased vascular permeability, pain signaling and inflammation, and is central to the kallikrein-kinin system. This page is educational and not medical advice.
Source & context
Biological / chemical source: Cleaved from kininogen by kallikrein enzymes
Primary research or clinical context: Vascular, inflammation and pain physiology research
Generation and receptors
Bradykinin (RPPGFSPFR) is cleaved from high-molecular-weight kininogen by plasma kallikrein. It acts mainly at the constitutive B2 receptor and, during injury, at the inducible B1 receptor, and is rapidly degraded by kininases including angiotensin-converting enzyme (ACE).
Why it matters
Because ACE also inactivates bradykinin, its accumulation explains the cough and angioedema seen with ACE-inhibitor drugs. The peptide is a key research model for vascular permeability, nociception and hereditary angioedema, where kallikrein-kinin signaling is dysregulated.
Sequence
One-letter sequence commonly cited for Bradykinin (educational; isoforms and modifications may differ):
RPPGFSPFR
Residues plotted ~100° apart around an α-helix — clustering of one color reveals an amphipathic face.
Structure & chemistry
Molecular identity & reference confidence
Source-supported reference
Reference values are taken from the cited molecular record or curated profile. A database match is not independent laboratory verification; modifications, counter-ions, and formulations can change the measured mass.
- Molecular form
- Bradykinin (source record; form not independently established)
- Species
- Not established by this molecular identity audit
- Termini (N / C)
- Not specified / Not specified
Average reference mass
Reference policy updated: 2026-10-05
- IUPHAR/BPS source snapshot · 2026-09-06
- PubChem molecular record · 2026-09-06
- Molecular formula
- C50H73N15O11
- Average reference mass
- ≈ 1,060.2
- PubChem CID: 439201
- IUPHAR ligand: 649
- ChEMBL: CHEMBL406291
- CAS RN: 58-82-2
- UNII: S8TIM42R2W
Chemistry values: PubChem, IUPHAR/BPS Guide to Pharmacology · fetched 2026-09-06.
Clinical development snapshot
ClinicalTrials.gov lists 73 registered studies with “Bradykinin” as an intervention (snapshot 2026-10-01). A registry footprint is not evidence of efficacy or approval.
| NCT | Title | Phase | Status | Updated |
|---|---|---|---|---|
| NCT06679881 | Long-Term, Open-label Study of Oral Deucrictibant Extended-Release Tablet for Prophylaxis Against Angioedema A | Phase 3 | enrolling by invitation | 2026-09-22 |
| NCT07266805 | Study of Oral Deucrictibant XR Tablet for Prophylaxis and Deucrictibant Soft Capsule for On-Demand Treatment o | Phase 3 | recruiting | 2026-09-21 |
| NCT07800338 | Evaluation Of The Effect Of Low-Level Laser Therapy On Masseter Muscle Versus Therapeutic Ultrasound On Patien | Not applicable | not yet recruiting | 2026-09-02 |
| NCT05630612 | ETA and AT1 Antagonism in ANCA-vasculitis (SPARVASC) | Phase 2 | active not recruiting | 2026-08-26 |
| NCT05047185 | Dose-ranging Study of Oral PHA-022121 for Prophylaxis Against Angioedema Attacks in Patients With Hereditary A | Phase 2 | terminated | 2026-08-17 |
| NCT07759141 | EAP for Deucrictibant Immediate-release | — | available | 2026-08-12 |
Bradykinin — reconstitution calculator
Enter how much peptide is in the vial and how much diluent (e.g. bacteriostatic water) is added. The tool returns the resulting solution concentration — and, for any amount you type, the volume it corresponds to. This is educational arithmetic, not a dosing recommendation.
Reference form: Bradykinin (source record; form not independently established)Average reference mass: 1,060.2 Da
Enter an amount to see the volume it corresponds to.
Educational concentration mathematics only. This tool does not recommend a dose, amount, or protocol, and nothing here is medical advice. Many peptides are not authorized by Health Canada for human use — see our reconstitution and bacteriostatic-water guides for context.
FAQ about Bradykinin
What is Bradykinin?+
Bradykinin is a nine-amino-acid signaling peptide of the kinin group, released from kininogen by kallikrein. Acting through B2 and B1 receptors, it drives vasodilation, increased vascular permeability, pain signaling and inflammation, and is central to the kallikrein-kinin system. This page is educational and not medical advice.
What Canadian product status is recorded for Bradykinin?+
Canadian product status for Bradykinin has not been verified in this profile. No verified record here does not mean no authorization exists. Status depends on the product, formulation and use; consult Health Canada's product records.
What is the typical length of Bradykinin?+
Bradykinin is commonly described as approximately 9 amino acids (Signaling peptide (kinin)).
Related peptides
References & further reading
- 1.Lepinski et al. (2000). Bradykinin levels in dental pulp by microdialysis. J Endod
- 2.Sachs et al. (2018). [Drug-induced angioedema : Focus on bradykinin]. Hautarzt
- 3.Takano et al. (2014). Intracellular and nuclear bradykinin B2 receptors. Eur J Pharmacol
- 4.Yin et al. (2021). Molecular basis for kinin selectivity and activation of the human bradykinin receptors. Nat Struct Mol Biol
- 5.Yi et al. (2024). Bradykinin receptor expression and bradykinin-mediated sensitization of human sensory neurons. Pain
- 6.Song et al. (2024). Bradykinin attenuates endothelial-mesenchymal transition following cardiac ischemia-reperfusion injury. Eur J Pharmacol
- 7.Francel (1992). Bradykinin and neuronal injury. J Neurotrauma
- 8.Siti-Zubaidah et al. (2024). Exploring bradykinin: A common mediator in the pathophysiology of sepsis and atherosclerotic cardiovascular disease. Vascul Pharmacol
- 9.PubChem — Bradykinin (CID 439201)
- 10.Wikipedia — Bradykinin