Fine structure and radioautography of rabbit photoreceptor cells.
Fine structure and radioautography of rabbit photoreceptor cells.
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兔感光细胞的精细结构和放射自显影。
DOI：
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发表时间：
1978
影响因子：
4.4
通讯作者：
A. H. Bunt
中科院分区：
文献类型：
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作者：
A. H. Bunt
成年兔子的视网膜包含两种类型的感光器。I型占主导地位，是典型的棒材。到目前为止，II型细胞的身份一直不确定。本研究表明，II型细胞具有一定的锥形形态特征，包括苍白的核，复杂的突触蒂，色素上皮的微绒毛包裹着外节的多个。II型外节段也是圆锥形的，因为一些椎间盘内的间隙与细胞外的间隙是独立的，更新的模式是弥漫性的，如放射自显影所示，糖和氨基酸是前体，并且本研究中发现的少数远端尖端脱落的例子主要发生在黑暗周期的早期。II型外段的内部被选择性地标记为3H-聚焦，而I型外段的内部在所有时间间隔内都未被这种糖标记。该标记可能反映了锥状外节中含有一种含焦糖蛋白的存在，这种蛋白在杆状外节中缺乏，可能代表一种视觉色素或其他内在分子。玻璃体内注射过氧化物酶后，一种无定形物质在连接纤毛的光感受器周围形成对称的套筒。这种纤毛相关物质在玻璃体内注射3H聚焦后的4小时内被特异性标记，在光感受器间基质显示显著标记之前，表明它是由含糖物质组成的。讨论了纤毛相关材料的可能功能，包括结构支撑和离子调节。
The retina of the adult rabbit contains two types of photoreceptors. Type I predominates and is a typical rod. The identity of the type II cell has been uncertain until now. This study demonstrates that the type II cell has certain conelike morphologic features including a pale nucleus, complex synaptic pedicel, and multiple wrappings of the outer segment by microvilli of the pigment epithelium. The type II outer segment is also conelike in that some intradisc spaces are patent to the extracellular space, that the pattern of renewal is diffuse as demonstrated radioautographically with sugar and amino acids as precursors, and that the few examples of distal tip shedding found in this study occur mainly in the early part of the dark cycle. The interior of the type II outer segment is labeled selectively with 3H-fucose, whereas the interior of the type I outer segment remains unlabeled with this sugar at all time intervals examined. The label probably reflects the presence of a fucose-containing glycoprotein in the conelike outer segment which is lacking in the rod outer segment and may represent a visual pigment or other intrinsic molecule(s). An amorphous material which forms a symmetric sleeve around the photoreceptor connecting cilium has been demonstrated after intravitreal injections of horeseradish peroxidase. This cilium-associated material is labeled specifically by 4 hr following intravitreal injection of 3H-fucose, before the interphotoreceptor matrix shows significant labeling, suggesting that it is composed of a sugar-containing material. Possible functions of the cilium-associated material, including structural support and ionic regulation, are discussed.