Navas V, O'Morchoe P J, O'Morchoe C C
Department of Biology, University of Puerto Rico at Mayaguez.
Lymphology. 1995 Mar;28(1):4-20.
Light and electron microscopy combined with morphometric analysis were used to investigate the distribution, extent and structure of lymphatic vessels in the head, body and tail of the rat pancreas. Serial sections 3-4 microns in thickness were cut from tissue fixed by perfusion. Alternate sections were processed for light microscopy. Intervening sections were left uncovered to be re-embedded and sectioned for electron microscopy as needed. Vessels with valves were tentatively identified as lymphatics using the light microscope, with final identification being made on adjacent sections by electron microscopy. The ultrastructure of the pancreatic lymphatic vessels was typical of lymphatics generally. Interlobular lymphatic vessels were present throughout the pancreas and were found to be associated primarily with blood vessels lying in connective tissue septa. Intralobular lymphatics were also seen but were comparatively rare. Only about 19% of the wall of the lymphatic system of the pancreas was in close relationship to acinar cells--none was closely related to the endocrine islets. The mean volume density of the system was 0.0012 microns3/microns3 and the profile density of lymphatics was 3.24/mm2. Special attention was paid to the areas of contact between adjacent endothelial cells. Open gaps of more than 30 nm in width were rare. Dilatations and associated cytoplasmic processes, suggestive of a type of intercellular transport, were seen in addition to the intracellular cytoplasmic vesicular system. The findings are consistent with the view that the lymphatic system of the pancreas does not have a specific role in the transport of pancreatic secretions other than the removal of macromolecules that may escape to the interstitium in small amounts under normal circumstances. The fine structure of the endothelial wall suggests that the mechanism of lymph formation in the pancreas is more comparable to that in other encapsulated organs such as the kidney and liver than to that in the dermis or diaphragm where fluid appears to enter lymphatics primarily by way of gaps between adjacent cells.
采用光镜和电镜结合形态计量分析的方法，研究大鼠胰腺头部、体部和尾部淋巴管的分布、范围及结构。从灌注固定的组织上切取厚度为3 - 4微米的连续切片。每隔一张切片用于光镜检查。中间的切片不覆盖，根据需要重新包埋并切片用于电镜检查。在光镜下初步将有瓣膜的血管鉴定为淋巴管，最终通过相邻切片的电镜检查进行确认。胰腺淋巴管的超微结构总体上是淋巴管的典型结构。小叶间淋巴管遍布整个胰腺，主要与结缔组织间隔中的血管相关。也可见小叶内淋巴管，但相对较少。胰腺淋巴系统壁只有约19%与腺泡细胞密切相关，无一与内分泌胰岛密切相关。该系统的平均体积密度为0.0012立方微米/立方微米，淋巴管的轮廓密度为3.24/平方毫米。特别关注相邻内皮细胞之间的接触区域。宽度超过30纳米的开放间隙很少见。除了细胞内的胞质小泡系统外，还可见到扩张及相关的细胞质突起，提示一种细胞间运输方式。这些发现与以下观点一致，即胰腺淋巴系统在胰腺分泌物的运输中没有特定作用，除了清除在正常情况下可能少量逸入间质的大分子。内皮细胞壁的精细结构表明，胰腺中淋巴形成的机制与其他被膜器官如肾脏和肝脏更相似，而与真皮或膈肌不同，在真皮或膈肌中，液体似乎主要通过相邻细胞之间的间隙进入淋巴管。
