Habold Caroline, Reichardt François, Foltzer-Jourdainne Charlotte, Lignot Jean-Hervé
Département d'Ecologie, Physiologie et Ethologie, CNRS, IPHC, 23 rue Becquerel, 67087 Strasbourg cedex 2, France.
Pflugers Arch. 2007 Nov;455(2):323-32. doi: 10.1007/s00424-007-0289-0. Epub 2007 Jul 19.
Intestinal villus atrophy through prolonged fasting was studied according to two different metabolic phases reached by fasting animals and characterized by (a) the mobilization of fat stores as body fuel and (b) an increase in protein catabolism for energy expenditure. The mechanisms involved in the rapid jejunal restoration after refeeding were also determined. Mucosal structural atrophy during fasting proved to worsen over the two phases due mainly to the retraction of the lacteals in the lamina propria, as observed through the immunolocalization of aquaporin 1 in the endothelial cells of the lymphatic vessels and the detachment of the basal membrane of the epithelial lining at the tip of the villi. Microvilli surface area is preserved through fasting, and apical PepT1 expression increases during both metabolic fasting phases. Refeeding after both fasting phases induces an increase in FATP4 accompanied by a rapid lipid uptake by the enterocytes at the tip of the villi and a rapid extension of the lamina propria due to inflated lymphatic vessels. These mechanisms were more prevalent in animals refed after the phase III fast and could be considered as the major processes allowing complete morphological restoration of the jejunum within only 3 days after refeeding.
根据禁食动物所达到的两个不同代谢阶段，对长期禁食导致的肠绒毛萎缩进行了研究，这两个阶段的特征分别为：(a) 动员脂肪储备作为身体燃料；(b) 蛋白质分解代谢增加以满足能量消耗。还确定了重新喂食后空肠快速恢复所涉及的机制。禁食期间的黏膜结构萎缩在这两个阶段中被证明会恶化，主要原因是固有层中乳糜管的回缩，这通过水通道蛋白1在淋巴管内皮细胞中的免疫定位以及绒毛顶端上皮衬里基底膜的脱离得以观察到。微绒毛表面积在禁食期间得以保留，并且在两个代谢禁食阶段顶端的肽转运蛋白1（PepT1）表达均增加。两个禁食阶段后的重新喂食均诱导脂肪酸转运蛋白4（FATP4）增加，同时绒毛顶端的肠细胞快速摄取脂质，并且由于淋巴管扩张导致固有层迅速扩展。这些机制在第三阶段禁食后重新喂食的动物中更为普遍，可被视为在重新喂食后仅3天内使空肠完全形态恢复的主要过程。
