Definition of bradykinin in US English:



  • A compound released in the blood in some circumstances that causes contraction of smooth muscle and dilation of blood vessels. It is a peptide comprising nine amino-acid residues.

    • ‘The profile parallels that observed for bradykinin stimulated smooth muscle cells.’
    • ‘Another component of the renin-angiotensin-aldosterone system is bradykinin, a vasoactive peptide metabolized by the same enzyme that converts angiotensin I to angiotensin II.’
    • ‘Vasodilators, such as acetylcholine and bradykinin, do not exert their effects upon the vascular smooth muscle cell in the absence of the overlying endothelium.’
    • ‘The peptide subfamily of GPCR contains receptors that bind a disparate array of peptides, such as angiotensin, bradykinin, opioid, somatostatin, and chemokines.’
    • ‘This class of receptors includes the angiotensin, bradykinin and vasopressin receptors.’


1940s: from Greek bradus ‘slow’ + kinēsis ‘motion’ + -in.