Prado I M M, Di Dio L J A, Miranda-Neto M H, Molinari S L, Macchiarelli G
Department of Morphophysiological Science, University of Maringá, Paraná, Brazil.
Ital J Anat Embryol. 2005;110(2 Suppl 1):77-86.
Collagen has an important role in controlling mechanical function and physiopathology of intestinal wall. Swine small intestine may be used as biomaterial source for tissue repairing. Changes of collagen arrangement and three-dimensional (3D) distribution may be related to the dissimilar biomechanical proprieties showed by different intestine tracts. 3D spatial distribution of collagen bundles of swine submucosal terminal ileum (SSTI) was studied by a correlated analysis of light (LM) and scanning electron microscopy (SEM) of NaOH macerated samples. Bundles of collagen fibers were greatly represented in the submucosa at the mesenteric border and also extended along the longitudinal folds beneath mucosa layer. Polarized LM of picrosirius stained samples evidenced yellow and red fibers (type I collagen), and green fibers (type III collagen). Silver-impregnated sections showed predominant brown-stained fibers and, in a smaller amount, black-stained ones. By SEM submucosal collagen, isolated by NaOH maceration, appeared arranged in wide bundles forming a complicated 3-D network. The bundles presented a sinuous course, opened and closed repeatedly forming meshes fashioned in a regular net. These observations originally demonstrated that 3-D distribution of SSTI collagen is different from that observed in other gut segments and species. The arrangement of SSTI collagen fibers that we observed seems to be morphofunctionally adjusted to provide appropriate resistance to mechanical forces and to assure compliance to deformations induced by intestinal wall motion. The studies for selection of optimal intestinal patches for surgical replacement should take into consideration the basic morphological evaluation of parietal collagen 3D distribution.
胶原蛋白在控制肠壁的机械功能和生理病理学方面具有重要作用。猪小肠可作为组织修复的生物材料来源。胶原蛋白排列和三维（3D）分布的变化可能与不同肠道段表现出的不同生物力学特性有关。通过对氢氧化钠浸渍样本的光学显微镜（LM）和扫描电子显微镜（SEM）相关分析，研究了猪黏膜下末端回肠（SSTI）胶原束的3D空间分布。胶原纤维束在肠系膜边界的黏膜下层大量存在，并沿黏膜层下方的纵向褶皱延伸。天狼星红染色样本的偏振光显微镜显示黄色和红色纤维（I型胶原）以及绿色纤维（III型胶原）。银浸染切片显示主要为棕色染色纤维，少量为黑色染色纤维。通过SEM观察，经氢氧化钠浸渍分离出的黏膜下胶原蛋白呈宽束状排列，形成复杂的三维网络。这些束呈现出蜿蜒的走向，反复开合形成规则网状的网孔。这些观察结果最初表明，SSTI胶原蛋白的三维分布与其他肠道段和物种中观察到的不同。我们观察到的SSTI胶原纤维排列似乎在形态功能上进行了调整，以提供对机械力的适当抵抗力，并确保适应肠壁运动引起的变形。选择用于手术替代的最佳肠片的研究应考虑壁层胶原蛋白三维分布的基本形态学评估。
