The basal lamina of the villous epithelium in the small intestine has numerous fenestrations, which are produced by leukocytes for their intraepithelial migration. We previously showed that these fenestrations change due to the dynamics of migrating leukocytes in response to dietary conditions and suggested the possibility that this change is related to the regulation of the absorption of large-sized nutrients such as chylomicrons. The present study was, thus, designed to investigate structural changes in basal lamina fenestrations in response to a high-fat diet. The ultrastructure of the intestinal villi in the rat upper jejunum was investigated by electron microscopy of tissue sections in both the normal and the high-fat diet groups, and the fenestrations in the villous epithelium of rat upper jejunum were studied by scanning electron microscopy of osmium macerated/ ultrasonicated tissues. The present study showed that free cells adhering to the fenestrations increased in the upper jejunum two hours after feeding high-fat diet and the size of the fenestrations in this region also increased after feeding high-fat diet for 2 days. This enlargement of fenestrations may play an important role in increasing the efficiency of lipid absorption by facilitating the movement of chylomicrons from the intercellular space to the lamina propria.

中文翻译：

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高脂饮食条件下大鼠肠道绒毛上皮基底层窗孔的动态变化。

小肠绒毛上皮的基底层有许多开窗，这些开窗是由白细胞上皮内迁移所产生的。我们以前表明这些开窗率的变化是由于饮食条件下白细胞迁移的动力学所致，并暗示这种变化可能与乳糜微粒等大型营养物质的吸收调节有关。因此，本研究旨在调查对高脂饮食响应的基底层窗孔的结构变化。通过电子显微镜观察正常和高脂饮食组大鼠上空肠肠绒毛的超微结构，通过扫描浸没/超声处理组织的扫描电镜观察大鼠上空肠绒毛上皮的开窗。本研究表明，饲喂高脂饮食两小时后，空腹上空附着于窗孔的游离细胞增加，而饲喂高脂饮食2天后该区域窗孔的大小也增加。开窗的这种扩大可能通过促进乳糜微粒从细胞间空间向固有层的移动，在增加脂质吸收的效率中起重要作用。本研究表明，饲喂高脂饮食两小时后，空腹上空附着于窗孔的游离细胞增加，而饲喂高脂饮食2天后该区域窗孔的大小也增加。开窗的这种扩大可能通过促进乳糜微粒从细胞间空间向固有层的移动，在增加脂质吸收的效率中起重要作用。本研究表明，饲喂高脂饮食两小时后，空腹上空附着于窗孔的游离细胞增加，而饲喂高脂饮食2天后该区域窗孔的大小也增加。开窗的这种扩大可能通过促进乳糜微粒从细胞间空间向固有层的移动，在增加脂质吸收的效率中起重要作用。