Li J, Kudsk K A, Janu P, Renegar K B
Department of Surgery, University of Tennessee at Memphis, USA.
Surgery. 1997 May;121(5):542-9. doi: 10.1016/s0039-6060(97)90109-4.
Our prior work shows that total parenteral nutrition (TPN) causes small intestinal gut-associated lymphoid tissue (GALT) atrophy, lowers small intestinal immunoglobulin A (IgA) levels, and impairs secretory IgA-mediated mucosal immunity of the upper respiratory tract. These experiments examine whether an isonitrogenous 2% glutamine-enriched TPN solution prevents these changes.
Institute of Cancer Research mice were randomized to chow (chow), intravenous feeding of a TPN solution (TPN), or glutamine-enriched TPN (glutamine) groups. After mice were fed for 5 days, lymphocytes were isolated from Peyer's patches, the intraepithelial layer, and lamina propria to determine cell yields and phenotypes. Total small intestinal IgA levels were analyzed by means of enzyme-linked immunosorbent assay. In a second series of experiments, mice underwent intranasal inoculation with H1N1 virus to establish immunity. After 3 weeks mice were randomized to chow, TPN, or glutamine groups. After feeding for 5 days, mice were rechallenged with intranasal virus and killed at 40 hours to determine viral shedding from the upper respiratory tract.
Total lymphocyte yield in the Peyer's patches, the intraepithelial layer, and lamina propria, small intestinal IgA levels, and the CD4+/CD8+ ratio in the lamina propria decreased with TPN but remained normal with glutamine. On rechallenge, 87% of the mice in the TPN group shed virus in nasal secretions, whereas only 38% of the glutamine-treated group (p < 0.05 versus TPN) and 7.1% of the chow group (p < 0.002 versus TPN) were virus positive.
Isonitrogenous supplementation of TPN with 2% glutamine improves IgA-mediated protection in the upper respiratory tract and normalizes GALT populations.
我们之前的研究表明，全肠外营养（TPN）会导致小肠肠道相关淋巴组织（GALT）萎缩，降低小肠免疫球蛋白A（IgA）水平，并损害分泌型IgA介导的上呼吸道黏膜免疫。这些实验旨在研究含2%谷氨酰胺的等氮TPN溶液是否能预防这些变化。
将癌症研究所的小鼠随机分为普通饲料组（普通饲料）、静脉输注TPN溶液组（TPN）或富含谷氨酰胺的TPN组（谷氨酰胺）。小鼠喂养5天后，从派尔集合淋巴结、上皮内层和固有层分离淋巴细胞，以确定细胞产量和表型。通过酶联免疫吸附测定法分析小肠总IgA水平。在第二系列实验中，小鼠经鼻接种H1N1病毒以建立免疫。3周后，将小鼠随机分为普通饲料组、TPN组或谷氨酰胺组。喂养5天后，对小鼠再次经鼻接种病毒，并在40小时后处死，以确定上呼吸道的病毒排出情况。
TPN组小鼠的派尔集合淋巴结、上皮内层和固有层的总淋巴细胞产量、小肠IgA水平以及固有层中的CD4+/CD8+比值均下降，但谷氨酰胺组保持正常。再次接种病毒后，TPN组87%的小鼠鼻腔分泌物中排出病毒，而谷氨酰胺治疗组仅38%（与TPN组相比，p<0.05），普通饲料组仅7.1%（与TPN组相比，p<0.002）的小鼠病毒呈阳性。
在TPN中补充2%的等氮谷氨酰胺可改善IgA介导的上呼吸道保护作用，并使GALT群体恢复正常。
