Bradykinin receptor (B1 and B2 subtypes) (BDKRB1 (B1 receptor); BDKRB2 (B2 receptor))

The bradykinin pathway centers around bradykinin, a small peptide that binds to two main G protein-coupled receptors: the bradykinin B1 receptor (BDKRB1), which is inducible upon tissue injury or inflammation, and the bradykinin B2 receptor (BDKRB2), which is constitutively expressed in most tissues[1][3]. Activation of these receptors leads to downstream signaling that triggers the release of second messengers, nitric oxide, prostaglandins, and upregulation of inflammatory cytokines (e.g., IL-6, IL-1β, IL-8, IL-2)[1][3]. The bradykinin pathway is critically involved in mediating pain (nociception), vasodilation, increased vascular permeability, and a broad range of inflammatory responses[3]. Overactivation, as seen in hereditary angioedema or during adverse drug reactions (e.g., ACE inhibitor-induced angioedema), causes excessive tissue swelling and inflammation[2][4]. The pathway is implicated in diverse diseases including cardiovascular disease, inflammatory disorders, certain types of cancer, and may contribute to severe manifestations of infections like COVID-19 by amplifying cytokine signaling and vascular leak[1][4]. Therapeutic agents targeting this pathway include bradykinin receptor antagonists, kallikrein inhibitors, and C1 esterase inhibitors[2][3][4].

Other names

Bradykinin B1 receptor (B1R)Bradykinin B2 receptor (B2R)B1 kinin receptorB2 kinin receptorBDKRB1BDKRB2Kinin B1 receptorKinin B2 receptor

Drugs targeting this pathway primarily act through antagonism of the B2 bradykinin receptor to treat bradykinin-mediated angioedema, inhibition of kallikrein to prevent the generation of bradykinin, or, preclinically, inhibition of the B1 receptor for chronic pain/inflammatory conditions.