Related Experiment Video

Updated: May 3, 2026

Development of a 68Gallium-Labeled D-Peptide PET Tracer for Imaging Programmed Death-Ligand 1 Expression
09:06

Development of a 68Gallium-Labeled D-Peptide PET Tracer for Imaging Programmed Death-Ligand 1 Expression

Published on: February 3, 2023

1.8K

Radiolabelled GLP-1 receptor antagonist binds to GLP-1 receptor-expressing human tissues

Beatrice Waser1, Jean Claude Reubi

  • 1Division of Cell Biology and Experimental Cancer Research, Institute of Pathology, University of Berne, PO Box 62, Murtenstrasse 31, 3010, Berne, Switzerland.

European Journal of Nuclear Medicine and Molecular Imaging
|February 13, 2014
PubMed
Abstract

Insights

A novel radioligand, (125)I-BH-exendin(9-39), effectively visualizes glucagon-like peptide 1 (GLP-1) receptors in both normal and tumor tissues. This antagonist tracer shows promise for developing new imaging agents for GLP-1 receptor-expressing conditions.

Area of Science:

  • Nuclear medicine
  • Molecular imaging
  • Endocrinology

Background:

  • Radiolabeled glucagon-like peptide 1 (GLP-1) receptor agonists are used for imaging benign insulinomas.
  • Antagonist tracers may offer superior targeting for somatostatin receptor tumors compared to agonists.

Purpose of the Study:

  • To evaluate (125)iodinated-Bolton-Hunter (BH)-exendin(9-39) antagonist tracers for in vitro visualization of GLP-1 receptor-expressing tissues.
  • To compare the antagonist tracer with the agonist tracer (125)I-GLP-1(7-36)amide in rat and human tissues.

Main Methods:

  • Receptor autoradiography was performed using (125)I-GLP-1(7-36)amide (agonist) and (125)I-BH-exendin(9-39) (antagonist) radioligands.
  • Studies were conducted on both human and rat tissues to assess tracer binding.

Main Results:

  • The (125)I-BH-exendin(9-39) antagonist, labeled at lysine 19, successfully identified GLP-1 target tissues and GLP-1 receptor-expressing tumors in humans and rats.
  • Binding affinity was high and comparable to the agonist tracer (125)I-GLP-1(7-36)amide.
  • Labeling at lysine 4 resulted in identification of rat GLP-1 receptors but not human receptors.

Conclusions:

  • The GLP-1 receptor antagonist exendin(9-39) labeled with (125)I-BH at lysine 19 is an effective radioligand for visualizing GLP-1 receptors.
  • This tracer identifies GLP-1 receptors in normal and tumor tissues in both rats and humans.
  • It provides a foundation for developing in vivo imaging agents for GLP-1 receptor-expressing tissues.

More Related Videos

Mechanisms Underlying Gut Hormone Secretion Using the Isolated Perfused Rat Small Intestine07:00

Mechanisms Underlying Gut Hormone Secretion Using the Isolated Perfused Rat Small Intestine

Published on: February 26, 2019

9.1K
Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors12:03

Receptor Autoradiography Protocol for the Localized Visualization of Angiotensin II Receptors

Published on: June 7, 2016

17.3K

Related Concept Videos

Glucagon-like Receptor Agonists01:24

Glucagon-like Receptor Agonists

Incretins include glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), which stimulate insulin secretion post-meals. In type 2 diabetes, GIP's efficacy is reduced, making GLP-1 a viable drug target. GIP originates from preproGIP.
GLP-1, when administered in high doses intravenously, triggers insulin secretion, inhibits glucagon release, slows gastric emptying, reduces food intake, and restores normal insulin secretion. However, its rapid inactivation by...
1.3K
G Protein-coupled Receptors01:15

G Protein-coupled Receptors

G Protein-Coupled Receptors or GPCRs are membrane-bound receptors that transiently associate with heterotrimeric G proteins and induce an appropriate response to sensory stimuli such as light, odors, hormones, cytokines, or neurotransmitters.
GPCRs are also called heptahelical, 7TM, or serpentine receptors, and consist of seven (H1-H7) transmembrane alpha-helices that span the bilayer to form a cylindrical core. The transmembrane helices are connected by three extracellular loops and three...
14.1K
Oral Hypoglycemic Agents: Glinides01:06

Oral Hypoglycemic Agents: Glinides

Repaglinide (Prandin) and Nateglinide (Starlix), known as glinides, are oral insulin secretagogues that stimulate insulin release from pancreatic β cells by closing the ATP-sensitive potassium channels (KATP channel). Repaglinide controls insulin release from pancreatic β cells by managing potassium efflux. It shares two binding sites with sulfonylureas and also has a unique site, indicating overlapping mechanisms of action. With a rapid onset and a 4-7 hour duration, it effectively...
1.0K