[Gut hormone secreting cells--unsolved problems]

Area of Science:

• Gastroenterology
• Cell Biology
• Neuroendocrinology

Background:

• Gut endocrine cells are bipolar paraneurons extending from the epithelial base to the luminal surface.
• These cells, also termed basal-granulated cells, produce and release peptidic and amine signaling substances.
• Release is triggered by luminal stimuli, with both endocrine and paracrine actions.

Purpose of the Study:

• To review the dual signaling roles of gut endocrine cells.
• To highlight the paracrine significance of gut endocrine cell secretions.
• To discuss the co-release of ATP and chromogranins alongside peptides and amines.

Main Methods:

• Review of existing literature on gut endocrine cell function.
• Analysis of signaling pathways involving gut endocrine cells.
• Examination of the secretory products of these cells.

Main Results:

• Gut endocrine cells release signaling substances in response to luminal stimuli.
• These substances act in both endocrine and paracrine fashions, influencing nearby elements.
• Co-secretion of ATP and chromogranins with peptides and amines occurs.
• Gut hormones have been observed being released into the gut lumen.

Conclusions:

• Gut endocrine cells play a crucial role in local and systemic signaling.
• The paracrine actions of gut endocrine cell secretions are particularly important.
• The partial exocrine function, involving luminal hormone release, warrants further mechanistic study.