Decrease in blood glucose and release of gut glucagon-like immunoreactive materials by bombesin infusion in the dog

Area of Science:

• Endocrinology
• Gastroenterology
• Metabolic Research

Background:

• Bombesin is a peptide with known effects on gastrointestinal and endocrine functions.
• Understanding bombesin's role in glucose homeostasis is crucial for metabolic research.

Purpose of the Study:

• To investigate the effects of synthetic bombesin on glucose metabolism and hormone release in dogs.
• To determine the origin and role of gut glucagon-like immunoreactive materials (GLI) in bombesin-induced metabolic changes.

Main Methods:

• Synthetic bombesin infusion in anesthetized normal and depancreatized dogs.
• Measurement of plasma glucose, insulin, glucagon-like immunoreactive materials (GLI), and glucagon immunoreactivity (GI).
• Intra-ileal glucose administration to assess GLI response.

Main Results:

• Bombesin infusion decreased plasma glucose and transiently increased insulin in normal dogs.
• Bombesin markedly stimulated GLI release from the intestine, with augmented response to ileal glucose.
• In depancreatized dogs, bombesin did not affect plasma glucose levels.
• Bombesin also stimulated glucagon release, likely of gastrointestinal origin.

Conclusions:

• Bombesin infusion lowers blood glucose in normal dogs, an effect dependent on the pancreas.
• Bombesin significantly enhances GLI release from the intestine.
• Gastrointestinal glucagon release is also stimulated by bombesin.
• A potential mechanism for bombesin's glucose-lowering effect involves GLI competition with glucagon at receptor sites.