Ohtani Y, Ohtani O, Nakatani T
Second Department of Internal Medicine, Okayama University School of Medicine, Japan.
Arch Histol Cytol. 1993 Aug;56(3):317-28. doi: 10.1679/aohc.56.317.
The present study demonstrated the three-dimensional microstructure of the rat diaphragm by scanning electron microscopy (SEM) of either intact or alkali-treated tissues, enzyme-histochemistry, and confocal laser scanning microscopy (LSM). The peritoneal and pleural surfaces of the diaphragm were covered with mesothelial cells studded with microvilli. Many round gaps were formed between the mesothelial cells. The submesothelial connective tissue contained voluminous, irregularly shaped lymphatics. Some of these lymphatics extended many funnel-like projections of their endothelia towards the pored region of the mesothelium. On coming into contact with the mesothelium, many of the lymphatic projections were perforated at their ends, thus giving rise to stomata connecting the peritoneal cavity and lymphatic lumen. Some projections ended blindly while plugging the mesothelial pores, thereby making visible some intercellular gaps in this contact. The subperitoneal sheet of the collagen fiber network possessed clusters of foramina which tightly fit the passage of the lymphatic projections. Confocal LSM of the diaphragm after intraperitoneal injection of FITC-dextran demonstrated the tracer both in the lymphatic lumina and in the connective tissue spaces. Our results indicate that peritoneal fluid is allowed to flow into the connective tissue spaces of the diaphragm through intercellular gaps and into lymphatics through stomata.
本研究通过对完整或经碱处理的组织进行扫描电子显微镜（SEM）、酶组织化学和共聚焦激光扫描显微镜（LSM）观察，展示了大鼠膈肌的三维微观结构。膈肌的腹膜和胸膜表面覆盖着布满微绒毛的间皮细胞。间皮细胞之间形成了许多圆形间隙。间皮下结缔组织含有大量形状不规则的淋巴管。其中一些淋巴管的内皮向间皮的孔隙区域伸出许多漏斗状突起。与间皮接触时，许多淋巴突起的末端有穿孔，从而形成连接腹膜腔和淋巴管腔的气孔。一些突起在堵塞间皮孔隙时盲端终止，从而在这种接触中可见一些细胞间隙。腹膜下胶原纤维网络片层有成群的小孔，紧密适配淋巴突起的通过。腹腔注射异硫氰酸荧光素标记葡聚糖后对膈肌进行共聚焦LSM观察，结果显示示踪剂存在于淋巴管腔和结缔组织间隙中。我们的结果表明，腹膜液可通过细胞间隙流入膈肌的结缔组织间隙，并通过气孔流入淋巴管。
