Akademik Veri Yönetim Sistemi
Revue de Medecine Veterinaire, cilt.160, sa.5, ss.252-257, 2009 (SCI-Expanded)
The purpose of this study was to investigate the histological structure and ultra-structure of conjunctiva associated lymphoid tissue (CALT) in cattle. Conjunctival tissues were sampled from 20 healthy animals in a slaughterhouse, near Ankara. Lymphoid structures were macroscopically revealed by acetic acid 3% application and were diffusely located in both the upper and lower palpebra conjunctivas. Solitary and/or aggregate lymphoid follicles and follicle-associated-epithelium (FAE) with squamous cells and without goblet cells constituted lymphoid zones. Some characteristic high endothelial venules (HEV) were observed within interfollicular areas and CD4+ and CD8+ T cells were mainly detected by immunohistochemistry in interfollicular and sub-epithelial regions. With electron microscopy, the FAE cells were characterized by short and irregular micro-folds in apical membrane and by deep invaginations of the baso-lateral membrane which surrounded packed inflammatory / immune cells (lymphocytes, granulocytes and macrophages). In thin sections obtained from animals which the eyes have been previously exposed to ferritin, ferritin particles were evidenced in apical invaginations, pinocytosis vesicles and vacuoles of FAE cells. The results suggest that CALT can be considered as the MALT component of conjunctiva in cattle.