Pharmacological characterization of the bradykinin B₂ receptor: inter‐species variability and dissociation between binding and functional responses

Abstract

1 The present study addresses the di erences in binding pro®les and functional properties of the human and rat bradykinin (BK) B 2 receptor using various kinin receptor peptide derivatives as well as the non-peptide receptor antagonists WIN 64338 (phosphonium, [[4-[[2-[[bis(cyclohexylamino)bound with a similar a nity to membranes of Chinese hamster ovary cells (CHO-K1) expressing the cloned human (hB 2 -CHO) or rat (rB 2 -CHO) B 2 receptor, human embryonic intestine cells (INT407) expressing the native B 2 receptor, human umbilical vein (HUV) and rat uterus (RU). WIN 64338 and FR173657 bound with a 3.8 ± 6.6 fold and 7.0 ± 16.3 fold higher a nity the rat than the human B 2 receptor, respectively. The a nity values of BK derivatives as well as non-peptide antagonists were reduced by 6 ± 23 fold in physiological HBSS compared to low ionic strength TES binding bu er. bound with a similar a nity the cloned and native bradykinin B 2 receptor in human (pK i of 8.66 and 8.59, respectively) and in rat (pK i 9.67 and 9.81, respectively). 6 In conclusion, we suggest that the binding bu er composition has to be taken into account when screening new compounds and that inter-species di erences should be considered when setting up animal models with the aim of developing bradykinin B 2 receptor antagonists as therapeutic agents.

Mechanism of Bradykinin-Induced Ca2+Mobilization in Murine Proximal Tubule Epithelial Cells

“…BK produced a concentration-dependent rise in [Ca 2ϩ ] i with a pEC 50 value of 8.39 Ϯ 0.04 (4 nM). This is the first reported EC 50 value for BK in the mouse proximal tubule epithelial cell and is very similar to EC 50 values or estimates reported for BK signaling in rabbit proximal tubules (Aboolian and Nord, 1988), in the murine inner medullary collecting duct cell line mIMCD-3 (Mukhin et al, 2001(Mukhin et al, , 2003, and in cultured rat mesangial cells (Bascands et al, 1991) -BK (also known as NPC 567) acted as a high-affinity competitive antagonist with a pK B value similar to its pK i value reported for the cloned rat B2 receptor but higher than pK B values reported for contraction of human umbilical vein and rat uterus (Paquet et al, 1999).…”

“…2A). The BK receptor subtype responsible for the rise in [Ca 2ϩ ] i was examined directly using selective B1 and B2 inhibitors (Bathon and Proud, 1991 (Paquet et al, 1999). These agents were tested against a concentration of BK (100 nM) that produced 80 to 90% of maximum response.…”

G protein-coupled receptors sense fluid shear stress in endothelial cells

“…Note that the IC 50 for the B2K chameleon (Fig. 5, which is published as supporting information on the PNAS web site) is significantly shifted to higher concentrations compared with the IC 50 of native B 2 (Յ 1 nM) (19)(20)(21); this shift is caused by the effects of the insertion of fluorescing proteins and was also observed earlier in the case of parathyroid hormone and ␣ 2A adrenergic receptor chameleons as a decrease in binding affinity and increase in the IC 50 (13). We have detected no change in FRET of B2K chameleon caused by exposure to B 2 -selective antagonist HOE140 (10 M), suggesting that constitutive activity of B2K is low.…”

Intermittent activation of bradykinin B2 receptors and mitochondrial KATP channels trigger cardiac postconditioning through redox signaling

“…To confirm B 2 receptor involvement, we used another B 2 antagonist, WIN64338, which is structurally unrelated to HOE140. Thus in Group 22 (PostC + WIN64338 group, n = 5), during the PostC protocol the hearts were perfused with 100 μM of WIN64338 [39]. In Group 23 (Intermittent BK + WIN64338; n = 5) the same concentration of WIN64338 was given during intermittent-BK infusion.…”