Aire Tom A, van der Merwe Mac
Department of Anatomy and Physiology, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, Republic of South Africa.
Anat Embryol (Berl). 2003 Apr;206(5):409-17. doi: 10.1007/s00429-003-0310-0. Epub 2003 Mar 21.
The structure of the efferent ducts of animals is known to vary from one species to another, it even varies between segments of the ducts in the same species. In the grasscutter or greater cane rat ( Thryonomys swinderianus), there are three segments of the efferent duct, based on their content of non-ciliated or principal cell types. Type I non-ciliated cell is present exclusively in the long proximal part of the duct, and exhibits a well-developed subapical endocytic apparatus as well as numerous oval or pleomorphic dense bodies. The type II non-ciliated cell predominates in the middle part of the duct, displays a poorly developed subapical endocytic apparatus but contains large, numerous vacuoles and dense bodies, all of which fill about two-thirds of the cell height. The type III non-ciliated cell, found in the epithelium of the terminal part of the duct, is poorly endowed with a subapical endocytic apparatus and contains no conspicuous endocytic vesicles or vacuoles. Only a few, small, dense bodies are present, if at all. The efferent duct of the cane rat is thus similar to that of man, the bull, goat and dog, in containing three varieties or types of non-ciliated cells. This report is the first to describe multiple non-ciliated cells in the epithelium of the efferent ducts of a rodent and, indeed, of a mammal smaller than the dog.
已知动物输出小管的结构因物种而异，甚至在同一物种的小管各段之间也有所不同。在非洲巨鼠（Thryonomys swinderianus）中，根据非纤毛细胞或主细胞类型的含量，输出小管可分为三段。I型非纤毛细胞仅存在于小管的长近端部分，具有发育良好的顶端下内吞装置以及许多椭圆形或多形性致密小体。II型非纤毛细胞在小管中部占主导，顶端下内吞装置发育不良，但含有大量大的液泡和致密小体，这些占据了细胞高度的约三分之二。III型非纤毛细胞存在于小管末端部分的上皮中，顶端下内吞装置较少，且不含明显的内吞小泡或液泡。即便有的话，也只有少数小的致密小体。因此，非洲巨鼠的输出小管与人类、公牛、山羊和狗的相似，都含有三种类型的非纤毛细胞。本报告首次描述了啮齿动物，实际上是比狗小的哺乳动物输出小管上皮中的多种非纤毛细胞。
