Given orally NPC 18884, but not HOE 140, caused graded inhibition of BK-induced nociception (mean ID50 value of 50 nmol/kg).In rats, NPC 18884 given i.p. prevented BK and carrageenan-induced hyperalgesia (mean ID50 values of 6 nmol/kg and 13 nmol/kg), without affecting the hyperalgesia induced by des-Arg9-bradykinin (DABK) or by prostaglandin E2 (PGE2).NPC 18884 given i.p. inhibited the mouse paw oedema induced by tyrosine8-bradykinin or by carrageenan, but had no effect on DABK-induced oedema in mice pre-treated with Escherichia coli endotoxin, or that induced by PGE2.
GAEE significantly inhibited the hyperalgesia induced by bradykinin or substance P in rat paw, but did not affect the hyperalgesia caused by carrageenan or prostaglandin E2.
The HE (3 to 100 mg kg(-1), p.o., 1 h) inhibited in a graded manner, the hyperalgesia induced by bradykinin (3 nmol/paw) or substance P (10 nmol/paw) in rat paw, with mean ED50 values of 54.5 and 53.7 mg kg(-1), respectively.
Hyperalgesia induced by prostaglandin E2 remained unaffected by FR173657.5.Blood pressure reflexes following i.p. instillation of bradykinin in anaesthetized rats were inhibited by FR173657 s.c. with an ID50 of 1.1 micromol kg(-1), while the peptidic B2 antagonist icatibant (Hoe-140; D-Arg0-[Hyp3, Thi5, D-Tic7, Oic8]-bradykinin) caused inhibition at significantly lower doses (ID50 8.5 nmol kg(-1) P < 0.001).Responses to hydrochloric acid i.p. remained unaffected by FR173657.6.
Post-treatment with S14080 dose-dependently antagonized the hyperalgesia induced by prostaglandin E2, bradykinin, dopamine and by the hyperalgesic cytokines reported to be released by carrageenin (tumour necrosis factor alpha, interleukin-1 and interleukin-8).3.
These data suggest that IL-10 limits the inflammatory hyperalgesia evoked by carrageenin and bradykinin by two mechanisms: inhibition of cytokine production and inhibition of IL-1 beta evoked PGE2 production.
Arachidonic acid induces a dose-dependent hyperalgesia that was found to be like bradykinin-hyperalgesia in untreated skin (prostaglandin E2-mediated and phospholipase A2-dependent).
These data are compatible with the suggestion that the prostaglandin products mediating BK and NE hyperalgesia differ, BKhyperalgesia being mediated by PGE2 and NE hyperalgesia by PGI2.
Pretreatment of the animals with BbCI (2.5 mg·kg(-1)), 30 min before carrageenan-induced inflammation, effectively reduced paw oedema and bradykinin release, neutrophil migration into the pleural cavity.
In vitro studies showed that C1-INH inhibits prekallikrein activation and bradykinin formation in a dose-dependent manner when added to the plasma of patients with HAE.
The combination of both bradykinin and substance P reporter substances with specific enzyme inhibitors will shed more light on biochemical pathways in inflammatory processes and pain.
Despite the efficacy of the on-demand treatment for the control of acute attacks of Hereditary Angioedema due to C1-Inhibitor Deficiency (C1-INH-HAE), the number and severity of attacks and the impairment in the quality of life of the affected patients have led to the development of a new monoclonal antibody, lanadelumab, directly addressed to the blockage of bradykinin, the principal mediator of vasodilation during angioedema attacks.
Neutrophils impact on processes preceding the formation of bradykinin, a major swelling mediator in hereditary angioedema (HAE), yet their potential role in HAE pathogenesis has not been sufficiently studied.
Uncontrolled production of BK due to inefficient regulation of the plasma contact system, increased activity of contact and coagulation factors or a deficient regulation of BK receptor-triggered intracellular signalling are on the basis of HAE pathology.
These results highlight a novel and specific approach to target PKK for the treatment of HAE and other diseases involving contact system activation and overproduction of bradykinin.
Exogenous administration of C1-INH is a rational way to restore the concentration and functional activity of this protein, regulate the release of bradykinin, and attenuate or prevent subcutaneous and submucosal edema associated with HAE.
One of these conditions is hereditary angioedema (HAE), a rare disease with characteristic attacks of aggressive tissue swelling due to unregulated production and activity of the inflammatory mediator bradykinin.
The Icatibant Outcome Survey (IOS; NCT01034969) is a Shire-sponsored, international, observational study monitoring the safety and effectiveness of icatibant, a bradykinin B2 receptor antagonist approved for the acute treatment of adults with hereditary angioedema with C1 inhibitor deficiency (HAE-C1-INH).
HAE is caused by SERPING1 gene mutations resulting in decreased or dysfunctional plasma protease C1 inhibitor (C1-INH) leading to a loss of inhibition of plasma kallikrein activity with subsequent cleavage of high-molecular weight kininogen and release of bradykinin.