Last reviewed 01/2021

Bradykinin is a vasoactive nonapeptide produced by the kinin system. It has a number of tissue actions:

  • vasodilation, possibly by a direct effect and via prostaglandin mediation
  • increase in vascular permeability by the opening of intercellular gaps in post-capillary venules
  • stimulation of phospholipase A2 and production of arachidonic acid
  • slow-onset, long-duration contraction of smooth muscle
  • pain; again histamine mediation is likely

Physiologically, bradykinin may be important in:

  • regulating blood supply to exocrine glands
  • inflammatory responses
  • pain production of pancreatitis via kallikrein release

Bradykinin is inactivated by angiotensin converting enzyme.