Department of Biology, Faculty of Science, Lund University, Lund 22362, Sweden.
World J Gastroenterol. 2017 Nov 14;23(42):7531-7540. doi: 10.3748/wjg.v23.i42.7531.
To investigate whether gut maturation could be induced precociously in an athymic T-cell deficient neonatal rat model.
Fourteen day-old athymic (nude) rats (NIH-1) were gavaged with either phytohaemagglutinin - a lectin from red kidney beans (PHA); trypsin - a protease (Prot); or water - vehicle (control) as a single dose on one day or once a day for 3-day. The nude rats were either nurtured by their mothers or cross-fostered by conventional foster dams of the Sprague-Dawley strain from days 3-5 after birth. At 17 d of age, 72 h after administration of the first treatment, intestinal macromolecular permeability was tested , prior to euthanasia, after which blood and gut organs were sampled.
Provocation with both, PHA and protease, resulted in increased gut growth and maturation in nude rat pups independent of nursing. Foetal-type enterocytes were replaced by non-vacuolated adult-type enterocytes in the distal small intestine epithelium. Decreased intestinal macromolecular permeability (gut closure) was observed, with reduced permeability markers (BIgG and BSA, < 0.001) in circulation. Increased pancreatic function, with an increased trypsin to protein ratio in pancreas homogenates, was observed independent of nursing in the nude pups. Immunostaining showed the presence of a few CD3-cells in the intestinal mucosa of the nude pups. The number of CD3-cells remained unaltered by provocation and no differences were observed between the nursing sets. Growth and vitality of the nude pups were dependent on nurturing, since cross-fostering by conventional dams increased their macromolecular absorptive capacity (BSA, < 0.05), as well as their passive immunity (RIgG, < 0.05).
Precocious gut maturation can be induced by enteral provocation in athymic rat pups, similarly to in euthymic pups, thus showing an independence from thymus-derived T-cells.
研究在无胸腺 T 细胞缺陷新生大鼠模型中，是否可以提前诱导肠道成熟。
将十四天大的无胸腺（裸鼠）（NIH-1）大鼠（n = 14）通过灌胃给予植物血球凝集素-来自红芸豆的凝集素（PHA）；胰蛋白酶-一种蛋白酶（Prot）；或水-载体（对照），作为单次剂量在一天或连续三天每天一次。从出生后第 3-5 天，裸鼠要么由其母亲养育，要么由 Sprague-Dawley 品系的常规代乳母鼠代养。在给药后第 17 天，即首次处理后 72 小时，进行肠道大分子通透性测试，然后安乐死，取样血液和肠道器官。
用 PHA 和蛋白酶刺激均导致裸鼠幼仔的肠道生长和成熟增加，而与哺乳无关。胎儿型肠上皮细胞被非空泡化的成人型肠上皮细胞取代。在远端小肠上皮中观察到肠道大分子通透性（肠道关闭）降低，循环中的通透性标志物（BIgG 和 BSA，<0.001）减少。在裸鼠中观察到胰腺功能增加，胰腺匀浆中胰蛋白酶与蛋白的比值增加，而与哺乳无关。免疫染色显示裸鼠肠道黏膜中存在少量 CD3 细胞。刺激对 CD3 细胞的数量没有影响，并且在哺乳组之间没有观察到差异。裸鼠的生长和活力取决于养育，因为由常规母鼠代养增加了它们的大分子吸收能力（BSA，<0.05）以及它们的被动免疫（RIgG，<0.05）。
通过肠内刺激可以在无胸腺大鼠幼仔中诱导早熟的肠道成熟，与在正常大鼠幼仔中相似，因此表明其独立于胸腺衍生的 T 细胞。
