Serotonin-containing cells in the gastrointestinal tract of newborn foals and adult horses.

The research focused on studying the presence and distribution of cells containing serotonin, a regulatory substance, in the gastrointestinal tract of newborn foals and adult horses to better understand its role, given that serotonin is known to influence gut muscle contraction and secretion, and is associated with various gastrointestinal disorders.

Introduction:

• This research aims to study the distribution and frequency of serotonin cells (also known as 5-HT immunoreactive cells) in the gastrointestinal tract (GIT) of newborn foals and adult horses.
• The focus on serotonin is due to its known role as a regulatory agent in gut muscle contraction and epithelial secretion, and its links to gastric ulcers, diarrhoea, and abdominal pain.
• Despite the high prevalence of these gastro-related issues in newborn foals and adult horses, there is a lack of concrete data about serotonin cell presence in their GIT.

Methods:

• The study employed an immunohistochemical approach to determine the distribution and relative frequency of serotonin cells in the GIT of newborn foals and adult horses.

Findings:

• In both foals and adults, a significant number of serotonin cells were observed in all portions of the GIT.
• A higher count of these cells was detected in the pyloric region (the lower part of the stomach that leads into the small intestine) and margo plicatus (the junction between the glandular and nonglandular part of the horse’s stomach) of the stomach in foals in comparison to adults.
• Additionally, the caecum (a pouch connecting the small and large intestines) and colon ascendens (the upward section of the large intestine) also displayed a higher serotonin cell count in foals than adults.

Conclusion and Future Research:

• The results shed light on the presence and distribution of serotonin cells in the GIT of foals and horses, highlighting potential physiological differences related to age.
• This provides grounds for further investigation into the role of serotonin cells during the milk diet phase or in the regulation of gastrointestinal growth/cell proliferation.
• These insights may also aid in understanding the occurrence and possible cell-mediated causes of gastric ulcers, especially in newborn foals.