Peptide Database

BK · Kallidin precursor fragment

Bradykinin is a 9-amino-acid vasoactive peptide of the kinin-kallikrein system. It produces vasodilation, increased vascular permeability, pain, and inflammation by acting on B1 and B2 receptors. ACE inhibitors (a major drug class) lower blood pressure partly by preventing bradykinin degradation. Icatibant, a B2 antagonist, is approved for hereditary angioedema. Research also implicates bradykinin in COVID-19 pathology (bradykinin storm hypothesis).