Schwarz Eveline, Saalmüller Armin, Gerner Wilhelm, Claus Rolf
Institut für Tierhaltung und Tierzüchtung (470), Fachgebiet Tierhaltung und Leistungphysiologie, Universität Hohenheim, Garbenstr. 17, 70599 Stuttgart, Germany.
Vet Immunol Immunopathol. 2005 May 1;105(1-2):125-39. doi: 10.1016/j.vetimm.2004.12.019.
It is well established that glucocorticoids are key regulators of the immune system and act as immunosuppressive agents in high concentrations. In the pig, effects on the gut immune system and trafficking of lymphocytes between tissues and blood plasma were not investigated so far. Twelve pigs of 70 kg were fed 0.4 mg portions of dexamethasone (Dexa) twice daily for 9 days or remained untreated (controls) and were sacrificed for tissue collection at the end of Dexa treatment. Another six pigs with jugular vein catheters were left untreated for 7 days (control period) and then received Dexa for 9 days. Blood was drawn twice during the control period and at days 3, 6 and 9 of the Dexa period for characterization of peripheral blood leukocytes. Cells were obtained from thymus, mesenteric lymph nodes, jejunal mucosa and Peyer's patches. Lymphoid cells from gut tissue were isolated from two fractions: the EDTA-fraction, containing the intraepithelial lymphocytes (IEL), and the Collagenase-fraction, containing the lamina propria lymphocytes (LPL). In all samples, cell counts and phenotypic characterization of cells by flow cytometry (FCM) were performed. In thymus, Dexa led to a more than 90% reduction of the absolute cell number, which was mainly found in the CD4+CD8+ subpopulation. Dexa effects on lymphocytes from mesenteric lymph nodes were less severe (50%) and led mainly to a decrease (71%) of B-lymphocytes. The number of lymphocytes in the EDTA-fraction (IEL) of the jejunal mucosa decreased significantly by 56% in the Dexa-treated animals compared to the controls, whereas the number of lymphocytes in the Collagenase-fraction (LPL) decreased only moderately. In the Peyer's patches, a decreasing tendency in the number of lymphocytes in the EDTA-fraction was observed which, however, was not significant. In blood, monocytes and granulocytes were significantly increased in an order of 60%. The data show that supraphysiological amounts of Dexa remarkably reduce cell numbers in thymus and also in the intraepithelial compartment of the jejunal mucosa and ileal Peyer's patches. In blood, a notable homeostasis was observed for several leukocyte populations whereas both monocytes and granulocytes increased.
糖皮质激素是免疫系统的关键调节因子，高浓度时可作为免疫抑制剂，这一点已得到充分证实。在猪身上，迄今为止尚未研究其对肠道免疫系统以及淋巴细胞在组织和血浆之间运输的影响。将12头体重70千克的猪，每天两次喂食0.4毫克地塞米松（Dexa），持续9天，或不进行处理作为对照（对照组），在Dexa处理结束时宰杀以收集组织。另外6头带有颈静脉导管的猪，7天不进行处理（对照期），然后接受Dexa处理9天。在对照期以及Dexa处理期的第3天、第6天和第9天采集两次血液，用于对外周血白细胞进行表征。细胞取自胸腺、肠系膜淋巴结、空肠黏膜和派伊尔结。肠道组织中的淋巴细胞从两个部分分离得到：EDTA部分，包含上皮内淋巴细胞（IEL）；胶原酶部分，包含固有层淋巴细胞（LPL）。在所有样本中，通过流式细胞术（FCM）进行细胞计数和细胞表型特征分析。在胸腺中，Dexa导致绝对细胞数减少超过90%，主要发生在CD4+CD8+亚群中。Dexa对肠系膜淋巴结淋巴细胞的影响较轻（50%），主要导致B淋巴细胞减少（71%）。与对照组相比，Dexa处理的动物空肠黏膜EDTA部分（IEL）中的淋巴细胞数量显著减少56%，而胶原酶部分（LPL）中的淋巴细胞数量仅适度减少。在派伊尔结中，观察到EDTA部分淋巴细胞数量有减少趋势，但不显著。在血液中，单核细胞和粒细胞显著增加，增幅约为60%。数据表明，超生理剂量的Dexa显著减少胸腺以及空肠黏膜和回肠派伊尔结上皮内区室中的细胞数量。在血液中，观察到几种白细胞群体有显著的内稳态，而单核细胞和粒细胞均增加。
