Department of Population Health Sciences, Faculty of Veterinary Medicine, Utrecht University, 3584CL Utrecht, The Netherlands.
Host-Microbe Interactomics, Department of Animal Sciences, Wageningen University & Research, 6700AH Wageningen, The Netherlands.
J Anim Sci. 2024 Jan 3;102. doi: 10.1093/jas/skae148.
The integrity of the intestinal barrier is crucial for regulating the passage of pathogens and toxins, while facilitating nutrient absorption. The everted gut sac technique, an ex-vivo technique, can be used to study interventions on barrier function. This cost-effective approach utilizes relatively large gut segments to study specific intestinal regions. Typically, intact (non-stripped) intestinal segments are used, but their use may underestimate permeability due to the medial positioning of blood vessels relative to the seromuscular layer and serosa. However, removing these layers risks physical damage, resulting in an overestimation of intestinal permeability. Therefore, we investigated the impact of stripping jejunal segments on permeability to fluorescein isothiocyanate-dextran (FITC, 4 kDa) and tetramethylrhodamine isothiocyanate-dextran (TRITC, 40 kDa), and on the absorption of glucose, lysine, and methionine in jejunal segments from 80 piglets at 8 d postweaning. Piglets were subjected to either high or low sanitary housing conditions and diets provoking intestinal protein fermentation or not, expected to influence intestinal permeability. Stripping of the seromuscular layer and serosa increased the passage of 4 kDa FITC-dextran (stripped vs. non-stripped; 1.1 vs. 0.9 pmol/cm2/min, P < 0.001), glucose (40.0 vs. 19.1 pmol/cm2/min, P < 0.001), lysine (2.5 vs. 2.0 nmol/cm2/min, P < 0.001), and methionine (4.1 vs. 2.7 pmol/cm2/min, P < 0.001). As permeability increased, the differences in methionine passage between stripped and non-stripped intestinal segments also increased (slope = 1.30, P = 0.009). The coefficients of variation were comparable between stripped and non-stripped intestines (over all treatments, stripped vs. non-stripped 38% vs. 40%). Stripping, by isolating mucosal processes without introducing additional variation, is thus recommended for studies on intestinal permeability or absorption.
肠屏障的完整性对于调节病原体和毒素的通过以及促进营养吸收至关重要。外翻肠囊技术是一种离体技术，可用于研究屏障功能的干预措施。这种具有成本效益的方法利用相对较大的肠段来研究特定的肠道区域。通常使用完整（未剥离）的肠段，但由于血管相对于黏膜肌层和浆膜位于中间位置，它们的使用可能会低估通透性。然而，去除这些层有物理损伤的风险，导致肠通透性的高估。因此，我们研究了剥离空肠段对荧光素异硫氰酸酯右旋糖酐（FITC，4 kDa）和四甲基罗丹明异硫氰酸酯右旋糖酐（TRITC，40 kDa）通透性以及断奶后 8 天 80 头仔猪空肠段对葡萄糖、赖氨酸和蛋氨酸吸收的影响。仔猪分别接受高或低卫生饲养条件和日粮，引起肠道蛋白质发酵或不引起肠道蛋白质发酵，预计会影响肠道通透性。剥离黏膜肌层和浆膜增加了 4 kDa FITC-右旋糖酐的通透性（剥离与未剥离；1.1 与 0.9 pmol/cm2/min，P < 0.001）、葡萄糖（40.0 与 19.1 pmol/cm2/min，P < 0.001）、赖氨酸（2.5 与 2.0 nmol/cm2/min，P < 0.001）和蛋氨酸（4.1 与 2.7 pmol/cm2/min，P < 0.001）。随着通透性的增加，剥离和未剥离肠段之间蛋氨酸通透性的差异也增加（斜率= 1.30，P = 0.009）。剥离和未剥离肠之间的变异系数相当（所有处理中，剥离与未剥离 38% 与 40%）。因此，剥离方法建议用于研究肠通透性或吸收，因为它可以在不引入额外变异的情况下分离黏膜过程。
