Cavallotti Carlo, Corrado Balacco Gabrieli, Feher Janos
Section of Anatomy, Department of Cardiovascular and Respiratory Sciences, University La Sapienza, Rome, Italy.
J Anat. 2005 Mar;206(3):243-7. doi: 10.1111/j.1469-7580.2005.00389.x.
The aim of the present study was to describe the ultrastructure of particular cells observed in the microvascular bed of the healthy human choroid, in close relation to the wall of the microvessels and resembling the periadventitial cells of other vascular areas of the human body. Serial sections of 12 fresh human eyes were studied by transmission electron microscopy. In all the eyes, the sections were obtained by cutting from the same zones (inner and outer choroid at the posterior pole of the eye). Standard techniques were used for transmission electron microscopy. Round cell bodies were found in the inner choroid at the posterior pole of the eye, mainly located in the intercapillary connective tissue. The cells were composed of an electron-transparent cytoplasm containing a few small mitochondria, and a dilated smooth surface of endoplasmic reticulum, at some points continuous with the nuclear membrane. These cells showed processes forming contact with the capillary wall. Some of these processes extended to the elastic layer of Bruch's membrane, but none had contact with the retinal pigment epithelium. A thin basement membrane surrounded both the cell bodies and processes. We believe that these cells are special cells resembling some type of periendothelial cells also localized in other microvascular districts of the human body. The close topographic correlation with the endothelial cells seems to indicate that these special cells play a role in the intrinsic control of proper endothelial functions.
本研究的目的是描述在健康人脉络膜微血管床中观察到的特定细胞的超微结构，这些细胞与微血管壁密切相关，类似于人体其他血管区域的血管外膜细胞。通过透射电子显微镜对12只新鲜人眼的连续切片进行了研究。在所有眼中，切片均取自相同区域（眼球后极的内脉络膜和外脉络膜）。透射电子显微镜采用标准技术。在眼球后极的内脉络膜中发现了圆形细胞体，主要位于毛细血管间结缔组织中。这些细胞由电子透明的细胞质组成，细胞质中含有一些小线粒体，内质网表面光滑且扩张，在某些点与核膜相连。这些细胞显示出与毛细血管壁形成接触的突起。其中一些突起延伸至布鲁赫膜的弹性层，但没有一个与视网膜色素上皮接触。一层薄的基底膜围绕着细胞体和突起。我们认为这些细胞是特殊细胞，类似于也存在于人体其他微血管区域的某种类型的周内皮细胞。与内皮细胞紧密的地形学相关性似乎表明这些特殊细胞在适当内皮功能的内在控制中发挥作用。
