Tags

Type your tag names separated by a space and hit enter

Characterization of kinin binding sites: identity of B2 receptors in the epithelium and the smooth muscle of the guinea pig ileum.
Can J Physiol Pharmacol. 1991 Jun; 69(6):818-25.CJ

Abstract

Binding of [125I-Tyr8]bradykinin (BK) was measured in homogenates of epithelial and smooth muscle layers of the guinea pig ileum. Binding assays were performed at 4 degrees C for 40 min (smooth muscle) or 90 min (epithelium) in 25 mM PIPES buffer at pH 6.8 in the presence of 1 mM 1,10-phenanthroline, 140 micrograms/mL bacitracin, 1 mM captopril, 1 mM dithiothreitol, and 0.1% bovine serum albumin. Specific binding of [125I-Tyr8]BK (0.32 nM) to epithelial and smooth muscle cell membranes was linearly related to protein concentration between 0.05 and 0.5 mg/mL. Equilibrium experiments showed that specific binding of [125I-Tyr8]BK was saturable and Scatchard analysis indicated the presence of a high affinity site with a Kd value of 1.6 nM and a Bmax of 156 fmol/mg of protein in the epithelial cell membranes. In smooth muscle membranes, Kd was 1.8 nM and the maximum number of binding sites was 58 fmol/mg of protein. Unlabelled peptides, namely bradykinin, [Tyr8]BK, [Hyp3]BK, D-Arg[Hyp3]BK, [Hyp3,Tyr(Me8)]BK, and kallidin displaced [125I-Tyr8]BK binding while other peptides, angiotensin II and substance P, had no effect. A series of B2-receptor antagonists displaced [125I-Tyr8]BK from specific binding sites with IC50 values ranging from 16 to 152 nM on epithelial cell membranes; similar values were obtained from smooth muscle cell membranes. These findings suggest that the binding sites in both preparations are of the B2 type. B1-receptor agonists and antagonists were found to be inactive at concentrations up to 10(-4) M. Results obtained in the two preparations were compared and a positive highly significant correlation was demonstrated between the two sets of data.(ABSTRACT TRUNCATED AT 250 WORDS)

Authors+Show Affiliations

Department of Pharmacology, Faculty of Medicine, University of Sherbrooke, Qué., Canada.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

1655182

Citation

Tousignant, C, et al. "Characterization of Kinin Binding Sites: Identity of B2 Receptors in the Epithelium and the Smooth Muscle of the Guinea Pig Ileum." Canadian Journal of Physiology and Pharmacology, vol. 69, no. 6, 1991, pp. 818-25.
Tousignant C, Guillemette G, Barabé J, et al. Characterization of kinin binding sites: identity of B2 receptors in the epithelium and the smooth muscle of the guinea pig ileum. Can J Physiol Pharmacol. 1991;69(6):818-25.
Tousignant, C., Guillemette, G., Barabé, J., Rhaleb, N. E., & Regoli, D. (1991). Characterization of kinin binding sites: identity of B2 receptors in the epithelium and the smooth muscle of the guinea pig ileum. Canadian Journal of Physiology and Pharmacology, 69(6), 818-25.
Tousignant C, et al. Characterization of Kinin Binding Sites: Identity of B2 Receptors in the Epithelium and the Smooth Muscle of the Guinea Pig Ileum. Can J Physiol Pharmacol. 1991;69(6):818-25. PubMed PMID: 1655182.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Characterization of kinin binding sites: identity of B2 receptors in the epithelium and the smooth muscle of the guinea pig ileum. AU - Tousignant,C, AU - Guillemette,G, AU - Barabé,J, AU - Rhaleb,N E, AU - Regoli,D, PY - 1991/6/1/pubmed PY - 1991/6/1/medline PY - 1991/6/1/entrez SP - 818 EP - 25 JF - Canadian journal of physiology and pharmacology JO - Can J Physiol Pharmacol VL - 69 IS - 6 N2 - Binding of [125I-Tyr8]bradykinin (BK) was measured in homogenates of epithelial and smooth muscle layers of the guinea pig ileum. Binding assays were performed at 4 degrees C for 40 min (smooth muscle) or 90 min (epithelium) in 25 mM PIPES buffer at pH 6.8 in the presence of 1 mM 1,10-phenanthroline, 140 micrograms/mL bacitracin, 1 mM captopril, 1 mM dithiothreitol, and 0.1% bovine serum albumin. Specific binding of [125I-Tyr8]BK (0.32 nM) to epithelial and smooth muscle cell membranes was linearly related to protein concentration between 0.05 and 0.5 mg/mL. Equilibrium experiments showed that specific binding of [125I-Tyr8]BK was saturable and Scatchard analysis indicated the presence of a high affinity site with a Kd value of 1.6 nM and a Bmax of 156 fmol/mg of protein in the epithelial cell membranes. In smooth muscle membranes, Kd was 1.8 nM and the maximum number of binding sites was 58 fmol/mg of protein. Unlabelled peptides, namely bradykinin, [Tyr8]BK, [Hyp3]BK, D-Arg[Hyp3]BK, [Hyp3,Tyr(Me8)]BK, and kallidin displaced [125I-Tyr8]BK binding while other peptides, angiotensin II and substance P, had no effect. A series of B2-receptor antagonists displaced [125I-Tyr8]BK from specific binding sites with IC50 values ranging from 16 to 152 nM on epithelial cell membranes; similar values were obtained from smooth muscle cell membranes. These findings suggest that the binding sites in both preparations are of the B2 type. B1-receptor agonists and antagonists were found to be inactive at concentrations up to 10(-4) M. Results obtained in the two preparations were compared and a positive highly significant correlation was demonstrated between the two sets of data.(ABSTRACT TRUNCATED AT 250 WORDS) SN - 0008-4212 UR - https://www.unboundmedicine.com/medline/citation/1655182/Characterization_of_kinin_binding_sites:_identity_of_B2_receptors_in_the_epithelium_and_the_smooth_muscle_of_the_guinea_pig_ileum_ L2 - https://cdnsciencepub.com/doi/10.1139/y91-123?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub=pubmed DB - PRIME DP - Unbound Medicine ER -