IMMUNOHISTOCHEMICAL AND HISTOMORPHOMETRIC RELATED SMALL INTESTINE CHANGES ASSOCIATED WITH SODIUM BUTYRATE SUPPLEMENT IN CHICKENS

Abstract

This study evaluated the effects of sodium butyrate (SB) supplementation on small intestine development in broiler chickens. Periodic acid-Schiff (PAS) and immunohistochemistry were used to undertake histological examinations of the duodenum, jejunum, and ileum. Duodenum, jejunum, and ileum histomorphometric data (villus length, crypt depth, goblet cell count), and interleukin-22 (IL-22) and toll-like receptor 8 (TLR8) immuno-stained area tissue coverage were quantified in control and SB supplemented groups. The histological changes in the SB supplemented group compared to the control group were as follows: There were increased villi lengths, widths, and crypt depths in the small intestine (duodenum, jejunum, and ileum). Increased numbers of goblet cells were observed, especially in the ileum. In addition, the lymphoid tissue within the small intestine was significantly larger (cross-section area=SB 34.8±0.5m2 vs control 13.2±0.5m2) and presented with more lymphoid nodules and more diffuse lymphoid tissue in the tunica submucosa, in the SB supplemented group compared to controls. Chickens do not have lymph nodes, therefore the mucosal-associated lymphoid tissue plays a major immunological role. Significant immunohistochemistry expression of IL-22 and TLR8 proteins were observed in the intestinal epithelial layer of the small intestine, which may play a role in protecting against many pathogens and gastrointestinal cancers. Imunohistokemične in histomorfometrične spremembe tankega črevesa, povezane z dodatkom natrijevega butirata pri piščancih Izvleček: Raziskava je ocenila učinke dodajanja natrijevega butirata (SB) na razvoj tankega črevesa pri piščancih brojlerjih. Za histološke preiskave dvanajstnika, teščega in vitega črevesa sta bili uporabljeni periodična kislina-Schiff (PAS) in imunohistokemija. Histomorfometrični podatki za dvanajstnik, tešče in vito črevo (dolžina resic, globina kripte, število čašastih celic) ter imunohistokemična obarvanost tkiva z interlevkinom-22 (IL-22) in Tollu podobnim receptorjem 8 (TLR8) so bili izmerjeni v kontrolni skupini in skupini, ki je prejemala dodatek SB. Histološke spremembe v skupini z dodatkom SB so bile v primerjavi s kontrolno skupino naslednje: v tankem črevesu (dvanajstniku, teščem in vitem črevu) so se povečale dolžine, širine in globine kript. Povečano je bilo število čašastih celic, zlasti v vitem črevesu. Poleg tega je bilo limfatično tkivo v tankem črevesu v skupini z dodatkom SB v primerjavi s kontrolno bistveno večje (površina prečnega prereza = SB 34,8 ± 0,5 m2, pri kontrolni skupini pa 13,2 ± 0,5 m2) in je pokazalo več limfatičnih vozličev ter bolj razpršeno limfatično tkivo v podsluznici. Piščanci nimajo bezgavk, zato ima limfatično tkivo sluznice črevesa pomembno imunološko vlogo. V epiteliju tankega črevesa smo opazili značilno imunohistokemično izražanje proteinov IL-22 in TLR8, kar lahko ima vlogo pri zaščiti pred številnimi patogeni in rakom prebavil. Ključne besede: IL-22; TLR8; črevesne resice; natrijev butirat; čašaste celice; limfatični vozliči