Dictionary > Bradykinin

Bradykinin

Definition
noun
A nonapeptide that is vasoactive causing blood vessels to dilate
Supplement
Bradykinin is a type of kinin. It is produced in the tissue and a potent vasodilator. It increases the permeability of post capillary venules. It acts on the endothelial cells and activate phospholipase A2. It also brings about non-vascular smooth muscle contraction (particularly in the bronchus and gut). It is also involved in pain metabolism. It is a nonapeptide since it is comprised of nine amino acid residues. Its amino acid sequence is Arg – Pro – Pro – Gly – Phe – Ser – Pro – Phe – Arg. It is very similar to kallidin in having the same sequence but with an additional N terminal lysine. It is formed through kinin-kallikrein system wherein the action of proteases on kininogens through the enzyme kallikrein results in the production of bradykinin. In humans, angiotensin-converting enzyme, aminopeptidase and carboxypeptidase N are the regulators involved in the breakdown of bradykinin.
Since bradykinin causes blood vessels to dilate it may also cause the blood pressure to drop particularly when prostacyclin, nitric oxide and endothelium-derived hyperpolarizing factor are subsequently released.
A rare disease, hereditary angioedema, is believed to be associated with the overactivation of bradykinin.1
Molecular formula:

  • C50H73N15O11

See also:

  • nonapeptide
  • Reference(s):

    1 Bas M, Adams V, Suvorava T, Niehues T, Hoffmann TK, Kojda G (August 2007). “Nonallergic angioedema: role of bradykinin”. Allergy 62 (8): 842–56.


    You will also like...

    Biosecurity and Biocontrol
    Biosecurity and Biocontrol

    This lesson explores the impact of biosecurity threats, and why they need to be identified and managed. Examples to incl..

    New Zealand Fauna
    New Zealand’s Unique Fauna

    Meet some of New Zealand's unique fauna, including endemic insects, frogs, reptiles, birds, and mammals, and investigate..

    Still Water Animals
    Still Water Animals

    Animals living in aquatic habitats have diversified and evolved through time. They eventually occupy ecological niches a..

    Protein (illustration)
    Protein Variety

    The sequence of amino acids determines the type of protein. Protein is synthesized according to the sequence of nucleoti..

    Bryophytes
    Bryophytes

    Bryophytes (nonvascular plants) are a plant group characterized by lacking vascular tissues. They include the mosses, th..

    Lights' Effect on Growth
    Lights’ Effect on Growth

    This tutorial elaborates on the effect of light on plant growth. It describes how different plants require different amo..

    Related Articles...

    No related articles found

    See all Related Topics