A bombesin immunoreactive peptide in milk

Area of Science:

• Gastroenterology
• Endocrinology
• Food Science

Background:

• Bombesin is a peptide hormone known to stimulate gastric acid secretion.
• The presence and origin of bombesin-like immunoreactivity in food sources, particularly dairy, remain largely unexplored.

Purpose of the Study:

• To investigate the presence and characteristics of bombesin-like immunoreactivity in bovine milk.
• To determine if milk consumption could be an exogenous source of bombesin-like peptides.

Main Methods:

• Immunoassay using bombesin-specific antiserum.
• Gel filtration chromatography and reversed-phase High-Performance Liquid Chromatography (HPLC).
• Enzymatic digestion (trypsin, alpha-chymotrypsin) and chemical modifications (urea, dithiothreitol, iodoacetamide).

Main Results:

• Bombesin-like immunoreactivity was detected in instant nonfat dry milk and bovine milk whey.
• The immunoreactivity was associated with a soluble peptide of approximately 3,200 molecular weight (Mr).
• Characterization revealed distinct chromatographic and enzymatic properties compared to gastrin-releasing peptide and amphibian bombesin.

Conclusions:

• Bovine milk is an exogenous source of bombesin-like immunoreactivity.
• This milk-derived peptide may contribute to post-consumption increases in gastric acid and gastrointestinal hormone levels.