SYNTHETIC CAPACITY OF RETICULOCYTES AS SHOWN BY RADIOAUTOGRAPHY AFTER INCUBATION WITH LABELED PRECURSORS OF PROTEIN OR RNA.
SYNTHETIC CAPACITY OF RETICULOCYTES AS SHOWN BY RADIOAUTOGRAPHY AFTER INCUBATION WITH LABELED PRECURSORS OF PROTEIN OR RNA.
复制标题
与标记的蛋白质或 RNA 前体一起孵育后，通过放射自显影显示网状细胞的合成能力。
DOI：
10.1016/0014-4827(63)90399-9
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发表时间：
1963
影响因子：
3.7
通讯作者：
B. Droz
中科院分区：
文献类型：
--
作者：
P. Pinheiro;C. P. Leblond;B. Droz
将大鼠血液与标记的蛋白质或RNA前体在37.5 °C下孵育1-30分钟。检查网织红细胞和其他血液元素是否存在放射性，如下所示。用亮甲酚蓝对孵育的血液进行活体上染色，并制备涂片。将涂片置于甲醇中（甲醇可固定网织红细胞，但可使网织红细胞网脱色），用放射自显影乳剂包被，曝光并显影。最后，涂片通过乳剂用姬姆萨染色（从而使网织蓝染色）。血液与蛋白质标记物3 H-亮氨酸或3 H-酪氨酸孵育后，普通（嗜酸性）红细胞不被标记，但约90%的网织红细胞和所有白色血细胞都被标记。这些结果表明，不仅有核细胞，而且无核网织红细胞也能够合成蛋白质。网织红细胞从3 H-亮氨酸中摄取的放射性与从3 H-酪氨酸中摄取的放射性之比与血红蛋白分子中亮氨酸与酪氨酸之比相似。这一发现表明，网织红细胞合成的蛋白质是血红蛋白，血液与RNA标记物3 H-尿苷、3 H-胞苷或3 H-腺嘌呤孵育后，嗜酸性红细胞和网织红细胞不被标记，但所有淋巴细胞和大多数中性粒细胞被标记。这些观察结果表明，只有有核细胞才能合成RNA。（所有细胞的3 H-5-甲基-胞嘧啶结果均为阴性。）因此，蛋白质合成发生在网织红细胞中，即使在这些细胞中检测不到RNA合成。因此，蛋白质合成不需要同时合成RNA。据推测，蛋白质合成所需的任何RNA都是由有核亲本细胞（正常母细胞）精心制作的，并持续存在于细胞质中，直到被使用。
Rat blood was incubated at 37.5 °C for 1–30 min with labeled precursors of protein or of RNA. The reticulocytes and other blood elements were examined for the presence of radioactivity, as follows. The incubated blood was supravitally stained with brilliant cresyl blue and smears prepared. The smears were placed in methanol (which fixed, but destained the reticulum of reticulocytes), coated with emulsion for radioautography, exposed and developed. Finally, the smears were stained with Giemsa through the emulsion (thus recoloring the reticulum blue).After incubation of blood with theprotein precursors3H-leucine or3H-tyrosine, the ordinary (acidophilic) erythrocytes do not, but about 90 per cent reticulocytes and all white blood cells do become labeled. These results indicate that not only nucleated cells, but also the nucleus-free reticulocytes are capable of protein synthesis. The ratio of radioactivity taken up by reticulocytes from3H-leucine over that taken up from3H-tyrosine is similar to the ratio of leucine over tyrosine in the hemoglobin molecule. This finding suggests that the protein synthesized in reticulocytes is hemoglobin.After incubation of blood with theRNA precursors3H-uridine,3H-cytidine or3H-adenine, acidophilic erythrocytes and reticulocytes do not, but all lymphocytes and most neutrophils do become labeled. These observations indicate that only nucleated cells are capable of RNA synthesis. (Results with3H-5-methyl-cytosine are negative for all cells.)Thus, protein synthesis occurs in reticulocytes even though no RNA synthesis is detectable in these cells. Hence, protein synthesis does not require simultaneous RNA synthesis. It is presumed that whatever RNA is required for protein synthesis is elaborated by the nucleated parent cell (normoblast) and persists in the cytoplasm until used.