CHRISTENSEN A K, FAWCETT D W
J Biophys Biochem Cytol. 1961 Mar;9(3):653-70. doi: 10.1083/jcb.9.3.653.
The interstitial tissue of the opossum testis includes interstitial or Leydig cells, macrophages, and small cells which morphologically resemble mesenchymal cells. The latter are thought to give rise to mature interstitial cells. The most prominent feature of the interstitial cell cytoplasm is an exceedingly abundant agranular endoplasmic reticulum. This reticulum is generally in the form of a meshwork of interconnected tubules about 300 to 450 A in diameter, but occasionally it assumes the form of flattened, fenestrated cisternae resembling those of pancreatic acinar cells, except for the lack of ribonucleoprotein particles on the surface of the membranes. The interstitial cells vary considerably in their cytoplasmic density. The majority are quite light, but some appear extremely dense, and in addition usually have a more irregular cell surface, with numerous small pseudopodia. These differences may well reflect variations in physiological state. Cytoplasmic structures previously interpreted as "crystalloids" consist of long bundles of minute parallel tubules, each about 180 A in diameter, which seem to be local differentiations of the endoplasmic reticulum. The mitochondria are rod-shaped, and contain a moderately complex internal membrane structure, and also occasional large inclusions that are spherical and homogeneous. The prominent juxtanuclear Golgi complex contains closely packed flattened sacs and small vesicles. The results of the present study, coupled with biochemical evidence from other laboratories, make it seem highly probable that the agranular endoplasmic reticulum is involved in the synthesis of the steroid hormones produced by the interstitial cell. This finding therefore constitutes one of the first functions of the agranular reticulum for which there is good morphological and biochemical evidence.
负鼠睾丸的间质组织包括间质细胞或莱迪希细胞、巨噬细胞以及形态上类似于间充质细胞的小细胞。后者被认为会发育为成熟的间质细胞。间质细胞胞质最显著的特征是存在极其丰富的无颗粒内质网。这种内质网通常呈相互连接的小管组成的网络状，直径约为300至450埃，但偶尔也会呈现出扁平的、有窗孔的池状，类似于胰腺腺泡细胞的池状结构，只是膜表面缺乏核糖核蛋白颗粒。间质细胞的胞质密度差异很大。大多数细胞相当浅，但有些看起来极其致密，而且通常细胞表面更不规则，有许多小伪足。这些差异很可能反映了生理状态的变化。以前被解释为“类晶体”的胞质结构由长束状的微小平行小管组成，每根小管直径约为180埃，似乎是内质网的局部特化。线粒体呈杆状，含有适度复杂的内膜结构，偶尔还有球形且均匀的大内含物。突出的核旁高尔基体复合体包含紧密排列的扁平囊泡和小泡。本研究的结果，加上其他实验室的生化证据，使得无颗粒内质网参与间质细胞产生的甾体激素合成的可能性极高。因此，这一发现构成了无颗粒内质网首批有充分形态学和生化证据支持的功能之一。
