A radioautographic study of the incorporation of iron 55 by the ameloblasts in the zone of maturation of rat incisors.
A radioautographic study of the incorporation of iron 55 by the ameloblasts in the zone of maturation of rat incisors.
复制标题
大鼠门牙成熟区成釉细胞掺入铁 55 的放射自显影研究。
DOI：
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发表时间：
1984
影响因子：
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通讯作者：
Hershey Warshawsky
中科院分区：
文献类型：
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作者：
A. Karim;Hershey Warshawsky
本研究旨在研究 55Fe 掺入大鼠门牙成熟成釉细胞的时间过程。雄性谢尔曼大鼠（100+/-5克）静脉内注射0.9毫居里的55Fe，并在注射后5分钟至7天的不同时间间隔通过灌注成对处死。切牙在 4.13% EDTA 二钠中脱矿，后固定在 1% 四氧化锇的醋酸维罗那缓冲液中，并嵌入 Epon 中。以相同方式处理仅注射生理盐水的对照大鼠的门牙。制备成熟区组织块的切片用于光学显微镜放射自显影观察。铁的最大掺入发生在该区域内 9 毫米处；在这个部位，成釉细胞含有很少的色素颗粒。注入 55Fe 后 2.5 小时观察到，在该区域深处约 5 毫米处，活性降至零。注射后 1 天到 7 天之间，在含有许多色素颗粒的细胞上发现了 55Fe 标记，而该区域 9 毫米内的细胞上的初始标记已经减少。这些数据表明，在任何给定时间，从 30 分钟到 4 小时，铁在大范围区域内进入成熟成釉细胞，在成熟开始后约 9 毫米处达到最大值。然而，在较长时间（1 天至 7 天）内，标记曲线会发生移动，并显示区域内超过 9 毫米的最大活性。
This study was designed to study the time course of the incorporation of 55Fe into the ameloblasts of maturation in rat incisors. Male Sherman rats (100 +/- 5 gm) were injected intravenously with 0.9 mCi of 55Fe and sacrificed in pairs by perfusion at various time intervals from 5 min to 7 days after injection. The incisors were demineralized in 4.13% disodium EDTA, postfixed in 1% osmium tetroxide in veronal acetate buffer, and embedded in Epon. Incisors from control rats injected with only physiological saline were treated in the same way. Sections from blocks of tissue in the zone of maturation were prepared for light microscope radioautographic observations. The greatest incorporation of iron occurred at 9 mm within the zone; at this site the ameloblasts contained few pigment granules. About 5 mm deeper into the zone the activity fell off to zero, as observed at 2.5 hr after injection of 55Fe. Between 1 day and 7 days after injection the 55Fe labeling was found over the cells containing many pigment granules, while the initial labeling over the cells within 9 mm of the zone had diminished. These data have shown that at any given time, from 30 min to 4 hr, the iron enters the maturation ameloblasts over a wide extent of the zone, reaching a maximum at about 9 mm from the onset of maturation. However, at longer times (1 day to 7 days) the labeling curve shifts and shows the greatest activity beyond 9 mm within the zone.