title: Transfer of carbonic anhydrase-positive particles from the follicle-associated epithelium to lymphocytes of Peyer's patches in foetal sheep and lambs.
abstract: Carbonic anhydrase cytochemistry of the ileal Peyer's patch in foetal and neonatal lambs has indicated secretion from the follicle-associated epithelium to the follicles. Reaction for carbonic anhydrase in the follicle-associated epithelium was found in the luminal plasma membrane, in cytoplasmic vesicles, and in vacuoles containing 50-nm membrane-bounded particles that seemed to be shed to the intercellular space. The lateral plasma membrane was negative for carbonic anhydrase, indicating that formation of carbonic anhydrase-positive particles was restricted to vacuoles. Administration of ferritin to ileal loops of sheep foetuses showed ferritin localized in vesicles and vacuoles of the follicle-associated epithelium followed by exocytosis, together with carbonic anhydrase-positive particles, into the indentations of the lateral cell border. The carbonic anhydrase-positive particles seemed to be transported to the centres of lymphoid follicles where many were attached to the plasma membrane of lymphocytes. Carbonic anhydrase-positive particles were also seen in vesicles and sometimes free in the cytoplasm of the lymphocytes or attached to their nuclear envelope. Light microscopically, carbonic anhydrase reactivity of the follicle-associated epithelium was associated with the early formation of the ileal Peyer's patch at about 100 days gestation. At this time the follicle-associated epithelium showed a strong luminal but at most a weak lateral staining. With further foetal development there was a progressive increase in the amount of carbonic anhydrase-positive reaction product in extracellular particles, both along the lateral cell borders of the follicle-associated epithelium and among the lymphocytes of the follicle centres.
authors.affiliation: Department of Pathology, Norwegian College of Veterinary Medicine, Oslo.
authors.forename: T
authors.initials: T
authors.lastname: Landsverk
authors.forename: W
authors.initials: W
authors.lastname: Trevella
authors.forename: L
authors.initials: L
authors.lastname: Nicander
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D002256:Carbonic Anhydrases / Q000378:metabolism*; D002450:Cell Communication; D004848:Epithelium / Q000378:metabolism* / Q000648:ultrastructure; D005293:Ferritins / Q000032:analysis; D007082:Ileum / Q000196:embryology / Q000254:growth & development / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism*; D008854:Microscopy, Electron; D010581:Peyer's Patches / Q000166:cytology / Q000378:metabolism*; D012756:Sheep
chemical_list: D005293:Ferritins; D002256:Carbonic Anhydrases