Distribution and ultrastructure of mast cells in the equine respiratory tract.

The research analyzes the distribution and microscopic characteristics of mast cells in the respiratory tract of horses. It finds that these cells are spread out throughout the respiratory tract but are primarily located in the nasopharynx, mostly in connective tissue. Ironically, these cells show similarities to human mast cells.

Objective of the Study

• The main objective of this study was to examine the distribution and ultrastructure of mast cells in the respiratory mucosa of horses.

Methods Used in the Study

• The research utilized both light and transmission electron microscope methodologies to observe the mast cells. This technique helped to establish the granularity, location, and finestructural characteristics of the mast cells.

Findings of the Study

• The research identified mast cells throughout the respiratory tract, with the highest density found in the nasopharynx.
• Between 57% to 94% of the studied cell population was located in the connective tissue of the lamina propria, which is a layer of loose connective tissue.
• Up to 20% of the mast cells were associated with the mucosal glandular tissue. There were also smaller numbers found within the surface epithelium and associated with the nodular lymphoid tissue.
• In peripheral lung tissue, 20% of the mast cells were associated with small airways. Meanwhile, 25% were associated with the lining of the pleura (the membrane surrounding the lungs), and 32% were associated with blood vessels.

Conclusion of the Study

• The ultrastructural features and fine structure of these mast cells mirrored those described in other species.
• The granules present in mast cells had two distinct types which bear resemblance to granules in human mast cells.