title: Reduced apoptosis in sheep ileal Peyer's patch is associated with low levels of follicle centre carbonic anhydrase reactivity.
abstract: Apoptosis in lymphoid follicles of the ileal Peyer's patch (IPP) in 21 sheep of two different age groups was visualized by the TdT-mediated dUTP nick end-labelling (TUNEL) method, and quantified using computer-assisted image analysis. The IPP follicle carbonic anhydrase (CA) reactivity was evaluated in the same samples. No significant differences with respect to apoptosis and CA reactivity were found between sheep aged 5 and 11 months. Individual variation in apoptotic activity correlated with the follicle centre CA reactivity. The group of animals found to have predominantly atypical ileal lymphoid follicles (more than 80% of total number of follicles) with features resembling jejunal Peyer's patch follicles, had lower number of apoptotic cells and reduced CA reactivity compared to the rest of the animals. The differences in CA reactivity in the follicle centres probably represent a variation in the presence of CA rich approximately 50 nm membrane-bounded particles known to be a feature of the sheep IPP. The present results suggest that the particles are involved in the modulation of the lymphocyte proliferation of the IPP follicles.
authors.affiliation: Department of Basic Sciences and Aquatic Medicine, Norwegian School of Veterinary Science, PO Box 8146 Dep., N-0033 Oslo, Norway. kai.lie@veths.no
authors.forename: Kai-Inge
authors.initials: KI
authors.lastname: Lie
authors.forename: Mona
authors.initials: M
authors.lastname: Aleksandersen
authors.forename: Aage
authors.initials: A
authors.lastname: Tverdal
authors.forename: Thor
authors.initials: T
authors.lastname: Landsverk
mesh_terms: D000367:Age Factors; D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D001402:B-Lymphocytes / Q000166:cytology / Q000201:enzymology; D002256:Carbonic Anhydrases / Q000378:metabolism*; D007082:Ileum / Q000166:cytology / Q000201:enzymology*; D007150:Immunohistochemistry / Q000662:veterinary; D020287:In Situ Nick-End Labeling / Q000662:veterinary; D010581:Peyer's Patches / Q000166:cytology / Q000201:enzymology*; D010641:Phenotype; D012756:Sheep / Q000378:metabolism*
chemical_list: D002256:Carbonic Anhydrases