Magalhães M C, Magalhães M M, Cimbra A
Cell Tissue Res. 1975 Nov 19;163(4):509-18. doi: 10.1007/BF00218496.
Two units of ACTH were administered intraperitoneally to young 20 gm-rats which received an intravenous injection of L-leucine-3H thirteen min later. ACTH-injected rats, and control rats which received the isotope alone, were killed at 2-, 10-, 30- and 60-min intervals. Electron microscope autoradiographs in control animals showed strong amino-acid uptake at pulse time (2-min) in the cytoplasm of adrenal zona fasciculata cells. Label was shared between the endoplasmic reticulum (ER) and mitochondria, and a lower but still considerable uptake was seen in nucleoli. At first chase time interval (10-min) cytoplasmic labelling declined, while nuclear and nucleolar labelling increased, both changing little thereafter, and there was a 10-30 min Golgi peak. ACTH administration provoked an overall increase in amino-acid incorporation into cytoplasm, nucleus and nucleolus at pulse time, with no changes in the distribution of the reactions among organelles. Intensification of labelling was most evident over nucleoli, the grain density of which was four-times as high as in controls. The short-term increase in ER and mitochondrial protein synthesis observed after ACTH injections was considered to be consistent with the hypothesis that most newly-formed proteins in these cells may be involved in the regulation of steroidogenesis. The marked increase in nucleolar labelling suggested the presence of proteins involved in RNA synthesis.
给体重20克的幼鼠腹腔注射2个单位的促肾上腺皮质激素（ACTH），13分钟后静脉注射L-亮氨酸-3H。注射ACTH的大鼠以及仅接受同位素注射的对照大鼠，分别在2分钟、10分钟、30分钟和60分钟的间隔时间处死。对照动物的电子显微镜放射自显影片显示，在脉冲时间（2分钟），肾上腺束状带细胞的细胞质中有强烈的氨基酸摄取。标记物在内质网（ER）和线粒体之间分布，核仁中的摄取量较低但仍相当可观。在最初的追踪时间间隔（10分钟），细胞质标记减少，而核和核仁标记增加，此后两者变化不大，并且在10 - 30分钟出现高尔基体峰。注射ACTH后，在脉冲时间氨基酸掺入细胞质、细胞核和核仁的总量增加，各细胞器之间反应分布没有变化。标记增强在核仁上最为明显，其颗粒密度是对照的四倍。ACTH注射后观察到的内质网和线粒体蛋白质合成的短期增加被认为与以下假设一致，即这些细胞中大多数新形成的蛋白质可能参与类固醇生成的调节。核仁标记的显著增加表明存在参与RNA合成的蛋白质。
