AJP - Gastrointestinal and Liver Physiology, Vol 256, Issue 4 747-G758, Copyright © 1989 by American Physiological Society

ARTICLES

Neuromedin B receptor in esophagus: evidence for subtypes of bombesin receptors

T. Von Schrenck, P. Heinz-Erian, T. Moran, S. A. Mantey, J. D. Gardner and R. T. Jensen
Digestive Diseases Branch, National Institute of Diabetes and Digestive and Kidney Diseases, Bethesda 20892.

To identify receptors for bombesin-related peptides in the rat esophagus, we measured binding of 125I-Bolton-Hunter neuromedin B (125I-BH-neuromedin B) and 125I-[Tyr4]bombesin to tissue sections from the rat esophagus and compared the results with those for rat pancreas. Esophagus bound both tracers, whereas pancreas bound only 125I-[Tyr4]bombesin. In each tissue binding was saturable, dependent on pH, on time, and on temperature, reversible, and specific. Autoradiography demonstrated binding of both tracers only to the muscularis mucosae of the esophagus and binding of 125I-[Tyr4]bombesin diffusely over pancreatic acini. In the esophagus, the relative potencies for inhibition of binding of both tracers were as follows: neuromedin B greater than bombesin greater than GRP = neuromedin C; similar relative potencies were found for causing contraction of muscle strips from whole esophagus and from the isolated muscularis mucosae. In pancreas tissue sections and dispersed acini, the relative potencies for inhibition of binding of 125I-[Tyr4]bombesin were as follows: bombesin greater than GRP = neuromedin C much greater than neuromedin B. Similar relative potencies were found for stimulation of enzyme secretion from dispersed pancreatic acini. Computer analysis in both tissues demonstrated only a single binding site. The present study demonstrates that rat esophagus muscle possesses specific receptors for bombesin-related peptides. Furthermore, this study shows that the esophageal bombesin receptors represent a previously unidentified class of bombesin receptors in that they have a higher affinity for neuromedin B than for bombesin. In contrast, the pancreatic bombesin receptors have, like all other bombesin receptors described to date, a high affinity for bombesin, but low affinity for neuromedin B.

This article has been cited by other articles:

				E. E. Ladenheim, M. Emond, and T. H. Moran Leptin enhances feeding suppression and neural activation produced by systemically administered bombesin Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2005; 289(2): R473 - R477. [Abstract] [Full Text] [PDF]

				D. Matusiak, S. Glover, R. Nathaniel, K. Matkowskyj, J. Yang, and R. V. Benya Neuromedin B and its receptor are mitogens in both normal and malignant epithelial cells lining the colon Am J Physiol Gastrointest Liver Physiol, April 1, 2005; 288(4): G718 - G728. [Abstract] [Full Text] [PDF]

				A. PANSKY, A. DE WEERTH, E. FASLER-KAN, J.-L. BOULAY, M. SCHULZ, S. KETTERER, C. SELCK, C. BEGLINGER, T. VON SCHRENCK, and P. HILDEBRAND Gastrin Releasing Peptide-Preferring Bombesin Receptors Mediate Growth of Human Renal Cell Carcinoma J. Am. Soc. Nephrol., August 1, 2000; 11(8): 1409 - 1418. [Abstract] [Full Text]

				R. R. Ryan, T. Katsuno, S. A. Mantey, T. K. Pradhan, H. C. Weber, D. H. Coy, J. F. Battey, and R. T. Jensen Comparative Pharmacology of the Nonpeptide Neuromedin B Receptor Antagonist PD 168368 J. Pharmacol. Exp. Ther., September 1, 1999; 290(3): 1202 - 1211. [Abstract] [Full Text]

				R. R. Ryan, H. C. Weber, W. Hou, E. Sainz, S. A. Mantey, J. F. Battey, D. H. Coy, and R. T. Jensen Ability of Various Bombesin Receptor Agonists and Antagonists to Alter Intracellular Signaling of the Human Orphan Receptor BRS-3 J. Biol. Chem., May 29, 1998; 273(22): 13613 - 13624. [Abstract] [Full Text] [PDF]

				L. L. Hampton, E. E. Ladenheim, M. Akeson, J. M. Way, H. C. Weber, V. E. Sutliff, R. T. Jensen, L. J. Wine, H. Arnheiter, and J. F. Battey Loss of bombesin-induced feeding suppression in gastrin-releasing peptide receptor-deficient mice PNAS, March 17, 1998; 95(6): 3188 - 3192. [Abstract] [Full Text] [PDF]