Atoji Y, Yamamoto Y, Suzuki Y
Laboratory of Veterinary Anatomy, Faculty of Agriculture, Gifu University, Japan.
Anat Rec. 1998 Nov;252(3):403-12. doi: 10.1002/(SICI)1097-0185(199811)252:3<403::AID-AR8>3.0.CO;2-F.
Apocrine sweat glands in the circumanal glands of the dog are not connected morphologically with the lobules of the circumanal glands. However, an apparent functional association has been demonstrated and it is possible that the apocrine sweat glands might serve as excretory ducts for degenerated polyhedral cells of the circumanal glands. In this study, we examined the ultrastructure of the apocrine sweat glands in the circumanal glands of the dog in an effort to define more precisely the relationship between the apocrine sweat glands and the circumanal glands. Paraffin sections stained with azan and sections after immunohistochemical staining with antibodies against actin were examined by light microscopy. Samples fixed by aldehyde perfusion were examined with the electron microscope. Diameters of apocrine sweat glands and height of cells in the secretory epithelium varied considerably. Immunohistochemical staining for actin was weakly positive in the supranuclear regions of secretory cells and very intense in myoepithelial cells. In secretory cells, the endoplasmic reticulum was well-developed. Multivesicular bodies were abundant and were discharged into lumens. Apocrine secretion and exocytosis were observed at luminal surfaces of secretory cells. There were three types of large granule in the cytoplasm: giant mitochondria without cristae; membrane-enclosed globules with or without myelin-like contents; and electron-dense, homogeneous, globular structures. Luminal surfaces were always covered with microvilli, and extensive folding of the cell membrane was found in basal regions. Bundles of actin filaments were dispersed throughout the cytoplasm. In the lumens of apocrine tubules, we observed shed secretory cells with well-preserved normal fine structures. We also noted the differentiation of secretory cells that was due to cell renewal. Apocrine sweat glands in the circumanal glands of the dog appear to be more active than those on the general body surface in terms of apocrine secretion, exocytosis, and the release of multivesicular bodies. Shed secretory cells containing large granules, as well as degenerated polyhedral cells from the circumanal glands, might contribute, to some extent, to the subtle composition of sweat from these apocrine sweat glands.
犬肛周腺中的顶泌汗腺在形态学上与肛周腺小叶并无连接。然而，已证实它们之间存在明显的功能关联，顶泌汗腺有可能作为肛周腺中退化多面体细胞的排泄管道。在本研究中，我们检查了犬肛周腺中顶泌汗腺的超微结构，以更精确地确定顶泌汗腺与肛周腺之间的关系。对用偶氮胭脂红染色的石蜡切片以及用抗肌动蛋白抗体进行免疫组织化学染色后的切片进行了光学显微镜检查。对经醛灌注固定的样本进行了电子显微镜检查。顶泌汗腺的直径和分泌上皮细胞的高度差异很大。肌动蛋白的免疫组织化学染色在分泌细胞的核上区域呈弱阳性，在肌上皮细胞中则非常强烈。在分泌细胞中，内质网发育良好。多泡体丰富并排入管腔。在分泌细胞的管腔表面观察到顶泌分泌和胞吐作用。细胞质中有三种类型的大颗粒：无嵴的巨大线粒体；有或没有髓磷脂样内容物的膜包小球；以及电子致密、均匀的球状结构。管腔表面总是覆盖有微绒毛，并且在基部区域发现细胞膜有广泛折叠。肌动蛋白丝束分散在整个细胞质中。在顶泌小管的管腔中，我们观察到具有保存完好的正常精细结构的脱落分泌细胞。我们还注意到由于细胞更新导致的分泌细胞分化。就顶泌分泌、胞吐作用和多泡体的释放而言，犬肛周腺中的顶泌汗腺似乎比体表其他部位的顶泌汗腺更活跃。含有大颗粒的脱落分泌细胞以及来自肛周腺的退化多面体细胞可能在一定程度上对这些顶泌汗腺分泌的汗液的微妙成分有贡献。
