Mucosal distribution of eosinophilic granulocytes within the gastrointestinal tract of horses.

The research study conducted an investigation on the distribution of eosinophilic granulocytes—a type of white blood cell—within the gastrointestinal tract of horses. This study aimed to provide a reference for the range and behavior of these eosinophilic granulocytes in the equine gastrointestinal mucosa, which could assist in the detection of changes caused by diseases.

Research Methodology

• The study examined gastrointestinal mucosal specimens from 14 adult horses which were euthanized for reasons other than gastrointestinal disease.
• These specimens were collected and categorized according to their anatomic regions.
• For histologic analysis, slides were stained with Luna’s eosinophil stain to determine the accumulation and distribution of eosinophils.
• The mucosal tissue was divided into 5 sections for each anatomic location. For each divided section, the percentage of eosinophils relative to the total count in all sections was determined.
• The number of eosinophils per square millimeter of mucosa was also counted to gauge the degree of eosinophil deposit.

Findings

• The lowest number of eosinophils were detected in the stomach.
• From the stomach, the eosinophil count increased steadily towards the cecum.
• The eosinophil count then decreased from the ascending colon to the small colon.
• Across all gastrointestinal sections, most eosinophils were located near the muscularis mucosae and were rarely found near or on the luminal surface of the mucosa.

Conclusions

• The distribution of eosinophils in the gastrointestinal tract of horses followed a pattern both within the mucosa and between different sections of the tract.
• The derived reference values and distribution data can aid in detecting changes in the eosinophil response in the equine gastrointestinal mucosa due to disease states.