LASANSKY A, DE ROBERTIS E
J Biophys Biochem Cytol. 1959 Mar 25;5(2):245-50. doi: 10.1083/jcb.5.2.245.
Alterations produced by iodoacetate in visual cells have been studied under the electron microscope. Lesions of the outer segments of the rods are visible as early as 3 hours after a single injection of 20 mg. iodoacetate per kg. body weight. After 6 hours the changes are more marked and consist then of disorganization, vesiculation, and lysis of the rod sacs. The inner segments of most rod cells show swelling and vacuolization of the matrix, the endoplasmic reticulum, and the Golgi complex. The mitochondria of the ellipsoid show a tendency to disintegrate. In some inner segments the changes consist primarily in an increase in density of the matrix and deposition of a granular material. The rod synapses are also affected, showing lysis of the synaptic vesicles and alterations of the synaptic membrane. With a second injection of 20 mg. iodoacetate per kg. body weight, all these changes become more marked and lead to complete destruction of the rod cells. The cones seem more resistant than the rods. A single injection produces no visible changes in the outer or inner segments of the cones. At cone synapses, however, there are changes consisting of fusion of synaptic vesicles and other membranous material to form large concentric membranes characteristic of myelin figures. A second dose of the drug causes complete destruction of the cone cells. All these, and other submicroscopic changes, are discussed in relation to various hypotheses put forward to explain the mode of action of iodoacetate on visual cells. The pronounced alterations of submicroscopic intracellular membranes suggest that the locus of action of iodoacetate may be a component widely dispersed throughout the visual cells and related, in some way, to the maintenance of these lipoprotein structures.
已在电子显微镜下研究了碘乙酸对视觉细胞产生的变化。单次注射每千克体重20毫克碘乙酸后，早在3小时就可见到视杆细胞外段的损伤。6小时后，变化更为明显，此时视杆细胞囊泡出现解体、形成小泡和溶解。大多数视杆细胞的内段显示基质、内质网和高尔基体肿胀并形成空泡。椭球体的线粒体有解体的趋势。在一些内段，变化主要表现为基质密度增加和颗粒物质沉积。视杆细胞突触也受到影响，表现为突触小泡溶解和突触膜改变。再次注射每千克体重20毫克碘乙酸后，所有这些变化都变得更加明显，并导致视杆细胞完全破坏。视锥细胞似乎比视杆细胞更具抵抗力。单次注射对视锥细胞的外段或内段没有可见变化。然而，在视锥细胞突触处，有变化包括突触小泡和其他膜性物质融合形成具有髓鞘样结构特征的大同心膜。第二次给药导致视锥细胞完全破坏。所有这些以及其他亚显微变化，都结合为解释碘乙酸对视觉细胞作用方式而提出的各种假说进行了讨论。亚显微细胞内膜的明显改变表明，碘乙酸的作用位点可能是一种广泛分布于整个视觉细胞的成分，并且在某种程度上与这些脂蛋白结构的维持有关。
