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...

    squirrel
    Animal Water Regulation

    Animals adapt to their environment in aspects of anatomy, physiology, and behavior. This tutorial will help you understa..

    Plant Water Regulation
    Plant Water Regulation

    Plants need to regulate water in order to stay upright and structurally stable. Find out the different evolutionary adap..

    Water Cycle
    The Water Cycle

    The water cycle (also referred to as the hydrological cycle) is a system of continuous transfer of water from the air, s..

    Adaptation Tutorial
    Adaptation Tutorial

    Adaptation, in biology and ecology, refers to the process or trait through which organisms or the populations in a habit..

    Plant biology
    Plant Biology

    Plantlife can be studied at a variety of levels, from the molecular, genetic and biochemical level through organelles, c..

    Early Earth
    The Origins of Life

    This tutorial digs into the past to investigate the origins of life. The section is split into geological periods in the..

    Related Articles...

    No related articles found

    See all Related Topics