Bradykinin receptor-like binding studied with iodinated analogues

Receptors for bradykinin in intact cultured human fibroblasts. Identification and characterization by direct binding study.

“…After incubation for 16 h at 4°C, antibody-bound 6-keto-PGF<,, was separated from uncomplexed tracer by the addition of 500 MA of an ice-cold 0.5% charcoal/0.05% dextran mixture and tubes were centrifuged (1,000 g, 10 min, 4°C). The supernatants were decanted into scintillation vials for radioassay of antibody-bound 6-keto-[3H]PGFI0 after addition of 10 (Fig. 2).…”

“…From indirect experimental approaches (structure-activity relationships, kinetic data), it has been concluded that bradykinin exerts its characteristic effects by interacting with one or more types of specific receptors on the cell surface (7)(8)(9). Recently, using 1251-[Tyrl]kallidin (10) or [3H]bradykinin (5,11) as radioligands, bradykininbinding sites with properties of physiologic bradykinin receptors have been identified in crude membrane preparations from several mammalian tissues. In intact tissues, bradykinin receptor stimulation appears to initiate a series of intracellular events, including activation of phospholipases A2 and C (12,13), the release of prostaglandins (PG)' (14)(15)(16), and accumulation of cyclic (c)AMP and cyclic guanosine monophosphate (16,17).…”

Bradykinin receptors in rat uterine smooth muscle: Studies using radiolabeled ligand binding.

“…Only limited reports using a direct binding technique are available (Reissmann et al 1977;Odya et al 1980). Direct binding techniques, similar to those reported here, have many advantages in characterising hormone-receptor In these experiments the initial concentration of 125I-Tyr8-bradykinin was 10-10 M, corresponding to the high affinity binding sites.…”

“…It was reported that 1251-Tyr8-bradykinin had only 24% of the activity of bradykinin as measured by the biological response in vitro of the rat uterus (Odya et al 1980). Odya et al (1980) concluded that 1251-Tyr8-bradykinin was an unsatisfactory ligand because of its susceptibility to kininase II activity (Chin et al 1975). However no evidence of breakdown of the radiolabeled ligand was found under our assay conditions.…”

“…In vitro direct binding studies using radiolabeled ligands have the advantages of localizing cellular receptors and of characterising specific receptor parameters. There have been few reports on specific bradykinin direct binding studies using a radiolabeled ligand (Reissmann et al 1977; Odya et al 1980).…”