Zhang Bolin, Zhong Qingzhen, Liu Ning, Song Peiyong, Zhu Peng, Zhang Caichao, Sun Zewei
Department of Biology and Agriculture, Zunyi Normal College, Ping'an Avenue, Hong Huagang District, Zunyi 563006, China.
College of Animal Science and Technology, Jilin Agricultural University, No. 2888, Xincheng Road, Jingyue District, Changchun 130118, China.
Animals (Basel). 2022 Jul 4;12(13):1729. doi: 10.3390/ani12131729.
The present study was conducted to investigate the effects of glutamine (Gln) supplementation on intestinal inflammatory reaction and mucosa barrier of broilers administrated with lipopolysaccharide (LPS) stimuli. A total of 120 1-d-old male broilers were randomly divided into four treatments in a 2 × 2 experimental arrangement, containing immune challenge (injected with LPS in a dose of 0 or 500 μg/kg of body weight) and dietary treatments (supplemented with 1.22% alanine or 1% Gln). The results showed that growth performance of broilers intra-abdominally injected with LPS was impaired, and Gln administration alleviated the adverse effects on growth performance induced by LPS challenge. Furthermore, Gln supplementation reduced the increased concentration of circulating tumor necrosis factor-α, interleukin-6 and interleukin-1β induced by LPS challenge. Meanwhile, D-lactic acid and diamine oxidase concentration in plasma were also decreased by Gln supplementation. In addition, the shorter villus height, deeper crypt depth and the lower ratio of villus height to crypt depth of duodenum, jejunum and ileum induced by LPS stimulation were reversed by Gln supplementation. Gln administration beneficially increased LPS-induced reduction in the expression of intestine tight junction proteins such as zonula occludens protein 1 (), and except for the in duodenum and in ileum. Moreover, Gln supplementation downregulated the mRNA expression of , , and in signaling pathway. Therefore, it can be concluded that Gln administration could attenuate LPS-induced inflammatory responses and improve intestinal barrier damage of LPS-challenged broilers.
本研究旨在探讨补充谷氨酰胺（Gln）对经脂多糖（LPS）刺激的肉鸡肠道炎症反应和黏膜屏障的影响。总共120只1日龄雄性肉鸡按2×2实验设计随机分为4组，包括免疫挑战（以0或500μg/kg体重的剂量注射LPS）和日粮处理（补充1.22%丙氨酸或1%Gln）。结果表明，腹腔注射LPS的肉鸡生长性能受损，补充Gln可减轻LPS挑战对生长性能的不利影响。此外，补充Gln降低了LPS挑战诱导的循环肿瘤坏死因子-α、白细胞介素-6和白细胞介素-1β浓度的升高。同时，补充Gln还降低了血浆中D-乳酸和二胺氧化酶的浓度。另外，Gln补充逆转了LPS刺激诱导的十二指肠、空肠和回肠绒毛高度缩短、隐窝深度加深以及绒毛高度与隐窝深度比值降低的情况。补充Gln有益地增加了LPS诱导的肠道紧密连接蛋白如闭合蛋白1（）、 和 表达的降低，但十二指肠中的 和回肠中的 除外。此外，补充Gln下调了 信号通路中 、 、 和 的mRNA表达。因此，可以得出结论，补充Gln可减轻LPS诱导的炎症反应，改善LPS挑战肉鸡的肠道屏障损伤。
