Pudney J, Canick J A, Mak P, Callard G V
Gen Comp Endocrinol. 1983 Apr;50(1):43-66. doi: 10.1016/0016-6480(83)90241-1.
The study of seminiferous tubule--Leydig cell interactions in relation to specific germ cell stages during the cycle of the seminiferous epithelium is extremely difficult in most mammalian species due to the continual presence of different spermatogenetic stages in the testis from the onset of puberty. The problem is also compounded by the uniform distribution of both seminiferous tubules and interstitial tissue throughout the entire testis. This difficulty can be circumvented, however, by studying certain species where there is a topographical distribution of germ cell stages within the testis. The urodele amphibian Necturus maculosus exhibits a breeding cycle during which a longitudinal wave of spermatogenesis occurs along the length of the testis, resulting in a spatial and temporal segregation of differentiating germ cells. Moreover, this topographical pattern of spermatogenesis is also reflected in the degree of development of adjacent Leydig cells. This anatomical arrangement allows distinct testicular regions to be obtained using a dissecting microscope. The isolated zones, containing germ cells and Leydig cells in various stages of development, were analyzed for 17 alpha-hydroxylase, C-17,20-lyase, and aromatase activities (key enzymes for the synthesis of androgens and estrogen), estrogen binding, and cytochrome P-450 content. Functional parameters were then correlated with the morphology of Leydig cells in the various zones observed by both light and electron microscopy. It was found that there existed a distinct correlation between the state of differentiation of the leydig cells, their steroidogenic potential, and the distribution of estrogen receptors. These results in Necturus indicate indicate in this species, at least, the steroidal microenvironment of different germ cell associations may be quite specific.
在大多数哺乳动物物种中，由于从青春期开始睾丸中不同生精阶段持续存在，研究生精上皮周期中特定生殖细胞阶段的生精小管-莱迪希细胞相互作用极其困难。生精小管和间质组织在整个睾丸中均匀分布也使问题更加复杂。然而，通过研究某些睾丸内生殖细胞阶段呈地形分布的物种，可以规避这一困难。有尾两栖动物黄斑美西螈具有繁殖周期，在此期间生精作用沿睾丸长度方向呈纵向波发生，导致分化中的生殖细胞在空间和时间上分离。此外，这种生精的地形模式也反映在相邻莱迪希细胞的发育程度上。这种解剖学排列使得可以使用解剖显微镜获得不同的睾丸区域。对分离出的含有处于不同发育阶段的生殖细胞和莱迪希细胞的区域进行了17α-羟化酶、C-17,20-裂解酶和芳香化酶活性（雄激素和雌激素合成的关键酶）、雌激素结合以及细胞色素P-450含量的分析。然后将功能参数与通过光学显微镜和电子显微镜观察到的不同区域中莱迪希细胞的形态相关联。发现莱迪希细胞的分化状态、它们的类固醇生成潜力与雌激素受体的分布之间存在明显的相关性。黄斑美西螈的这些结果表明，至少在该物种中，不同生殖细胞组合的类固醇微环境可能相当特殊。
