Histochemical and Immunohistochemical Investigations on Pyloric Tonsil in Turkeys (Meleagris gallopavo)

Structural patterns of pyloric tonsil in turkeys (Meleagris gallopavo) were investigated in this study. Turkeys, less resistant to disease than chickens, are a crucial source of protein with low cholesterol levels and a high protein/calorie ratio. Pyloric tonsil, involved in the chicken defense barrier, is a component of GALT. To evaluate the specific region, adult turkeys were taken from slaughterhouses. Crossman's modified triple staining demonstrated the general histological structure, PAS revealed the density of goblet cells synthesizing mucus, and Safranin O showed the capsule around the follicles. The width of lymphoid follicles in the pyloric tonsil (204.0±22.33) differed significantly from that of the middle part of the duodenum (111.7±4.741). It was noticed that the specific area harbors T cells, B cells, and follicular dendritic cells. Interfollicular regions were infiltrated with CD3+T cells, but the CD268+B cells occupied primarily germinal centers. However, it was noticed that T cells were present in germinal centers and some B cells in the interfollicular region. Anti-Vimentin antibody revealed follicular dendritic cells in the pyloric zone. It was noted that the epithelial layer of the pyloric tonsil is devoid of CK18-positive cells. Findings of the semi-thin section indicated that some columnar epithelial cells were stained differently in the transition zone (lymphoepithelium). To sum up, a pyloric region in turkeys is structurally dissimilar to pyloric tonsils detected in chicken, chukar partridge, and duck. More research is needed to reveal the effect of pyloric tonsil on the alimentary tract in poultry in terms of defense mechanisms.