Postnatal sequential changes in islet morphology and insulin secretion of normal hamsters

Area of Science:

• Endocrinology
• Developmental Biology
• Pancreatic Physiology

Background:

• The postnatal development of the endocrine pancreas is crucial for metabolic regulation.
• Understanding species-specific developmental timelines is essential for comparative physiology.

Purpose of the Study:

• To investigate the postnatal development of the endocrine pancreas in Syrian golden hamsters.
• To characterize changes in insulin secretion and islet cell composition during development.
• To establish a baseline for future studies on pancreatic growth and differentiation.

Main Methods:

• Analysis of insulin secretion from isolated pancreatic islets in response to varying glucose concentrations.
• Identification and quantification of pancreatic hormone-secreting cells (insulin, glucagon, somatostatin, pancreatic polypeptide).
• Histomorphometric analysis of endocrine pancreas volume and islet size at different ages (1, 8, and 24 weeks).

Main Results:

• Glucose-induced insulin secretion showed a delayed maximal response in younger hamsters (20 mM glucose) compared to adults (8 mM glucose).
• Increased endocrine pancreas volume and islet number were observed in 1-week-old hamsters relative to older animals.
• Islet volume significantly increased by 8 weeks of age, but the proportion and size of individual cell types remained consistent across age groups.

Conclusions:

• The endocrine pancreas in hamsters achieves adult characteristics relatively late post-birth.
• Morphological maturation of the endocrine pancreas precedes the full development of its secretory response to glucose.
• These findings provide foundational data for studying the regulation of pancreatic islet development and function.