Andonian S, Hermo L
Department of Anatomy and Cell Biology, McGill University, Montréal, Québec, Canada.
J Androl. 1999 Jan-Feb;20(1):158-76.
Principal cells show marked structural differences in the proximal, middle, and distal regions of the vas deferens, reflective of diverse functional activities. In the present study, we performed electron microscopy to examine the structural features of principal cells using glutaraldehyde-fixed, Epon-embedded material, while functional parameters were examined using light microscopic immunocytochemistry on Bouin-fixed, paraffin-embedded material. In the proximal region, the cuboidal principal cells resembled those of the cauda epididymidis, but few clear cells and occasional narrow cells were present. In the middle region, principal cells often contained blebs of their apical cytoplasm containing vesicular and tubular profiles. These blebs extended far from the cell surface and appeared to be liberated into the lumen, suggesting an apocrine type of secretion. In the distal region, dilated intercellular spaces containing numerous membranous profiles of different shapes and sizes were noted between adjacent principal cells and overlying basal cells. The use of an anti-aquaporin-1 antibody revealed an intense reaction over the endothelial cells of numerous vascular channels in the lamina propria. Taken together, these observations suggested water transport from the lumen of the vas deferens via the dilated spaces to underlying vascular channels, the function of which may be to concentrate sperm. The infranuclear cytoplasm of principal cells of this region showed whorls of smooth endoplasmic reticulum (sER). Large intracytoplasmic cavities were found within the sER aggregates, and these contained membranous profiles that appeared to peel off from the surrounding sER elements. Various images of such cavities closely juxtaposed to the lateral plasma membrane suggested that the membranous profiles of the intercellular spaces were derived from them. Use of anti-3beta-hydroxysteroid dehydrogenase antibody revealed an intense reaction over principal cells of the vas deferens, as well as over the blebs in the lumen of the vas deferens, which is indicative of the steroid synthesis performed by these cells. The release of sER membranous profiles into the dilated spaces and the presence of blebs in the lumen may represent a means of transporting steroids that are destined for different sites out of the principal cells. Steroids in the blebs would be ultimately destined for utilization by luminal sperm, while those steroids in the dilated spaces are designed for utilization by muscle layers of the lamina propria. In summary, principal cells of the vas deferens appear to be involved in synthesis and secretion of steroids and in eliminating water from the lumen of the vas deferens.
主细胞在输精管的近端、中间和远端区域呈现出明显的结构差异，这反映了其多样的功能活动。在本研究中，我们使用戊二醛固定、环氧树脂包埋的材料进行电子显微镜检查，以观察主细胞的结构特征，同时使用光镜免疫细胞化学方法对经Bouin固定、石蜡包埋的材料进行功能参数检测。在近端区域，立方形的主细胞类似于附睾尾部的主细胞，但透明细胞较少，偶尔可见窄细胞。在中间区域，主细胞的顶端细胞质常含有含有囊泡和管状结构的小泡。这些小泡从细胞表面延伸很远，似乎释放到管腔中，提示一种顶浆分泌类型。在远端区域，相邻主细胞与覆盖的基底细胞之间可见扩张的细胞间隙，其中含有许多不同形状和大小的膜性结构。使用抗水通道蛋白-1抗体显示，固有层中许多血管通道的内皮细胞有强烈反应。综合这些观察结果表明，水从输精管腔通过扩张的间隙转运至下方的血管通道，其功能可能是浓缩精子。该区域主细胞的核下细胞质显示出滑面内质网（sER）的漩涡状结构。在sER聚集体内发现大的胞质内腔，其中含有似乎从周围sER成分剥离的膜性结构。这种腔与外侧质膜紧密相邻的各种图像表明，细胞间隙的膜性结构源自于此。使用抗3β-羟基类固醇脱氢酶抗体显示，输精管主细胞以及输精管腔内的小泡有强烈反应，这表明这些细胞进行类固醇合成。sER膜性结构释放到扩张的间隙以及管腔中存在小泡可能代表一种将类固醇转运出主细胞至不同部位的方式。小泡中的类固醇最终将供管腔中的精子利用，而扩张间隙中的那些类固醇则供固有层的肌肉层利用。总之，输精管主细胞似乎参与类固醇的合成与分泌以及从输精管腔中清除水分。
