Chemical Properties
white fine crystalline powder
Uses
Bradykinin Acetate elicits vasoconstriction, a systemic blood pressure reflex, a stimulation of respiration, and contraction of the nictitating membrane. Bradykinin plays an important role in the regulation of fluid and electrolyte balance, smooth muscle contraction, vasodilation and capillary permeability.
Biological Activity
bradykinin (acetate) is a well-known 9-amino acid endogenous vasoactive peptide and a systemic vasodilator [1].bradykinin is a potent endothelium-dependent vasodilator, leading to the reduction in blood pressure. it also induces contraction of non-vascular smooth muscle in the bronchus and gut, increases vascular permeability and is also involved in the mechanism of pain. bradykinin is an inflammatory mediator. the bradykinin b1 receptor is expressed only as a result of tissue injury and plays a role in inflammation. the bradykinin b2 receptor is constitutively expressed and participates in bradykinin's vasodilatory role.in cultured endothelial cells, bradykinin promoted a rapid dissociation of the enos:b2 receptor complex [2]. in the mouse gastrointestinal tract and pancreas, bradykinin stimulated extravasation from postcapillary venules by two- to sevenfold by interacting with b2 receptors and stimulating tachykinin release from sensory nerves [3].in healthy men, bradykinin (100-3200 ng/kg min) dose-related increased plasma concentrations of 6-oxo-pgf1a , the stable hydrolysis product of prostacyclin (pgi2). so bradykinin may have a use as a probe of pg12 production in vivo in pathological states [1].
Biochem/physiol Actions
Bradykinin is a pro-inflammatory peptide that acts through G-protein-coupled receptors. It activates sphingolipid metabolism. Fibroblasts treated with bradykinin produce a rapid and important increase in ceramide which is followed by a transient rise in sphingosine content. The peptide also increases ceramide cellular content by rapidly mobilizing neutral glycolipids. Bradykinin plays an important role in the regulation of fluid and electrolyte balance, smooth muscle contraction, vasodilation and capillary permeability. The bradykinin potentiators, which possess no bradykinin activity themselves, enhance the activity of bradykinin.
in vivo
Application of 1 μM bradykinin acetate to the ovary produces significant decreases in heart rate and mean arterial pressure. In vagotomized animals, application of 1 μM bradykinin acetate to the ovary produces bradycardia and hypotension similar to the responses evoked when vagal innervation is intact[4].Vascular bradykinin acetate can improve pancreatic microcirculation and hemorheology in rats with severe acute pancreatitis. The pancreatic microcirculatory blood flow volume and velocity in the vascular bradykinin acetate treatment group increase gradually after 48 h[5].PI3K/Akt signaling pathway activation induced by bradykinin administration reduces the activity of GSK-3β and MAPK, and reduces NF-x03BA; B level in the nucleus, thereby inhibiting TF expression. Consistent with this, intraperitoneal injection of C57/BL6 mice with bradykinin also inhibits the thrombus formation induced by ligation of inferior vena cava[3].
IC 50
Bradykinin B2 Receptor (B2R); Human Endogenous Metabolite
References
[1]. barrow se, dollery ct, heavey dj, et al. effect of vasoactive peptides on prostacyclin synthesis in man. br j pharmacol. 1986 jan;87(1):243-7.
[2]. ju h, venema vj, marrero mb, et al. inhibitory interactions of the bradykinin b2 receptor with endothelial nitric-oxide synthase. j biol chem. 1998 sep 11;273(37):24025-9.
[3]. figini m, emanueli c, grady ef, et al. substance p and bradykinin stimulate plasma extravasation in the mouse gastrointestinal tract and pancreas. am j physiol. 1997 apr;272(4 pt 1):g785-93.
