Magalhàes M M, Coimbra A
J Cell Biol. 1970 Oct;47(1):263-75. doi: 10.1083/jcb.47.1.263.
Glycogen is present in the rabbit retina in monoparticulate form. Beta particles ( approximately 229 A) are abundant in Müller cell cytoplasm, particularly in its inner portion, decreasing in number outwards along the cell. They are slightly larger ( approximately 250 A) and much scarcer in neurons, though regularly present in the juxtanuclear Golgi region of ganglion cells. When the retina was incubated in a glucose-free medium, it was rapidly depleted of native glycogen. On further incubation in medium containing glucose-(3)H plus unlabeled glucose, glycogen reappeared in the form of beta particles of the same size and distribution as native ones, while radioautography revealed the appearance of amylase-labile radioactivity in the same locations. This newly formed glycogen was not associated with any particular organelle. The rate of synthesis, as judged from the amount of radioactivity, was high in the inner portion of Müller cells and declined uniformly toward the cell outer end, following a logarithmic gradient. The rate of synthesis was low in ganglion cells, at best approaching values in the outer portion of Müller cells. The concentration of glycogen in the inner portion of Müller cells is consistent with the view that it may be the source of glucose for the anaerobic glycolysis prevailing in the inner retina.
糖原以单颗粒形式存在于兔视网膜中。β颗粒（约229埃）在 Müller 细胞胞质中丰富，特别是在细胞内部，沿细胞向外数量减少。它们在神经元中稍大（约250埃）且稀少得多，不过在神经节细胞的核旁高尔基体区域有规律地存在。当视网膜在无葡萄糖培养基中孵育时，其天然糖原会迅速耗尽。在含有葡萄糖 -（3）H 加未标记葡萄糖的培养基中进一步孵育时，糖原以与天然糖原大小和分布相同的β颗粒形式重新出现，而放射自显影显示在相同位置出现了对淀粉酶敏感的放射性。这种新形成的糖原不与任何特定细胞器相关。从放射性量判断，合成速率在 Müller 细胞内部较高，并沿对数梯度向细胞外端均匀下降。神经节细胞中的合成速率较低，最多接近 Müller 细胞外部的值。Müller 细胞内部的糖原浓度与以下观点一致，即它可能是视网膜内层占主导的无氧糖酵解的葡萄糖来源。
