Study of the effects of aging on macromolecular synthesis in mouse steroid secreting cells using microscopic radioautography.
Study of the effects of aging on macromolecular synthesis in mouse steroid secreting cells using microscopic radioautography.
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使用显微放射自拍照研究衰老对小鼠类固醇分泌细胞大分子合成的影响。
DOI：
10.1358/mf.2000.22.1.795795
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发表时间：
2000
影响因子：
--
通讯作者：
F. Gao
中科院分区：
文献类型：
--
作者：
T. Nagata;M. Itô;Y. Liang;F. Gao
增龄对ddY小鼠肾上腺皮质细胞和睾丸间质细胞DNA、RNA和蛋白质合成的影响（从产前第19天到出生后第1、3、7、14天，出生后第1和6个月以及第1和2年）在用[3 H]-胸苷标记后使用光镜和电镜（EM）放射自显影进行检查，[3 H]-尿苷和[3 H]-亮氨酸。注射[~ 3 H]-胸腺嘧啶核苷后，肾上腺标记细胞的百分比在胚胎19天的皮质和髓质的肾小球中最大，在出生后1天的皮质的束状核和网状核中最大，并随着年龄的增长而逐渐下降。电镜放射自显影结果显示，在皮层的3个区带中，未标记细胞的胞质中较标记细胞的胞质中更常见一些发达的细胞器，如光滑面内质网、高尔基体、带管状嵴的线粒体和脂滴等。衰老对注射[3 H]-尿苷后肾上腺RNA合成的影响显示，肾上腺所有类型的细胞都被标记。在每个细胞中，银颗粒位于细胞核和细胞质上，并且在细胞核中比细胞质中更致密。皮质和髓质颗粒数在胎龄19天最高，从出生后14天到出生后1年，随着年龄的增长，颗粒数逐渐减少。在皮质中，银颗粒的数量是较高的球状体比在其他区域从胎儿19天至1年和颗粒计数较高的髓质在胚胎阶段相比，出生后的阶段。标记的线粒体数量和标记指数随增龄而增加。睾丸间质细胞[3 H]-胸腺嘧啶核苷标记指数在胚胎期和生后早期较低，6月龄时略有上升，9月龄时达到高峰，并在衰老过程中维持在较高水平。[~ 3 H]-尿苷标记的间质细胞核和胞质上的银颗粒的数量从胚胎第19天开始观察，从第3个月开始增加。从成年到衰老，[3 H]-尿苷掺入维持在高水平的细胞核和细胞质中相对较低。还检查了老化对Leydig细胞中[3 H]-亮氨酸掺入的影响。胚胎期和生后早期的标记指数没有明显差异，但从6个月开始，细胞质和细胞核中的银颗粒数量增加，并维持在较高水平，直到衰老。根据这些结果，可以得出结论，衰老对类固醇分泌细胞如肾上腺皮质细胞和小鼠睾丸Leydig细胞中DNA、RNA和蛋白质合成的影响与随着衰老观察到的激素变化相关。
The effects of aging on DNA, RNA and protein synthesis in adrenal gland cortical cells and testicular Leydig cells of ddY mice at various ages (from prenatal day 19 to postnatal days 1, 3, 7, 14, months 1 and 6 and 1 and 2 years after birth) were examined using light and electron microscopic (EM) radioautography after labeling with [3H]-thymidine, [3H]-uridine and [3H]-leucine. The percentage of the labeled cells in the adrenal glands after [3H]-thymidine injection was greatest in the zona glomerulosa of the cortex and the medulla on embryonic day 19, in the zona fasciculata and zona reticularis of the cortex on postnatal day 1 and gradually decreased with aging. EM radioautography revealed that well developed cell organelles such as smooth surfaced endoplasmic reticulum, Golgi apparatus, mitochondria with tubular cristae and lipid droplets were more frequently observed in the cytoplasm of unlabeled cells as compared to cells labeled with [3H]-thymidine in the three zones of the cortex. The effects of aging on RNA synthesis in adrenal glands after [3H]-uridine injection revealed that all types of cells of the adrenal gland were labeled. In each cell, silver grains were localized over the nuclei and cytoplasm and were more dense in the nuclei than the cytoplasm. Grain counts were highest in the cortex and medulla on fetal day 19 and then gradually decreased with aging from postnatal day 14 to 1 year after birth. In the cortex, the number of silver grains was higher in the zona glomerulosa than in the other zones from fetal day 19 to 1 year and grain counts were higher in the medulla in the embryonic stage as compared to the postnatal stages. However, the number of labeled mitochondria and the mitochondrial labeling index increased with aging. The [3H]-thymidine labeling index in the Leydig cells of the testis was low at embryonic and early postnatal stages, increased slightly at 6 months and reached a peak at 9 months which was maintained at a relatively high level in senescence. The number of the silver grains over the nuclei and cytoplasm of Leydig cells due to [3H]-uridine labeling was observed from embryonic day 19 and increased from month 3 onwards. From adult to senescence, [3H]-uridine incorporation was maintained at high levels in the nuclei and was relatively low in the cytoplasm. The effects of aging on [3H]-leucine incorporation in Leydig cells were also examined. The labeling indices between embryonic and early postnatal stages showed no obvious differences although the number of the silver grains in both cytoplasm and nucleus increased from 6 months onwards and was maintained at high levels until senescence. From these results, it was concluded that the effects of aging on DNA, RNA and protein synthesis in steroid secreting cells such as adrenal gland cortical cells and testicular Leydig cells of mice correlated with the hormonal changes observed with aging.