MORPHOLOGICAL CHANGES PANCREAS AFTER OF MELATONIN'S EFFECT IN DIFFERENT SEASONS.

Area of Science:

• Endocrinology
• Histology
• Chronobiology

Background:

• Melatonin is a hormone with diverse physiological effects.
• Seasonal variations can influence biological processes.
• Pancreatic function is crucial for digestion and metabolism.

Purpose of the Study:

• To investigate the seasonal effects of exogenous melatonin on rat pancreas morphology.
• To compare the impact of melatonin administration in spring versus autumn.

Main Methods:

• Young rats were administered 5 mg/kg of exogenous melatonin daily for 28 days.
• Morphometric analysis was performed on pancreatic tissues.
• Changes in exocrine and endocrine pancreas components were evaluated.

Main Results:

• Spring melatonin administration increased acinar size, epithelial height, exinocyte area, and nucleoli count, while reducing connective tissue.
• Autumn melatonin administration decreased acinar size, epithelial height, and exinocyte area, but increased exinocyte number and interlobular connective tissue.
• Both spring and autumn melatonin increased Langerhans islet size and endocrinocyte density, indicating enhanced endocrine function.

Conclusions:

• Melatonin exhibits season-dependent effects on the exocrine pancreas, stimulating it in spring and potentially inhibiting it in autumn.
• Melatonin consistently enhances the functional activity of the endocrine pancreas regardless of season.
• These findings highlight the importance of considering seasonal factors in melatonin's physiological actions.