Electron microscopic radioautographic study on mitochondrial RNA synthesis in adrenal cortical and medullary cells of aging mice  

作　　者：Tetsuji Nagata 

机构地区：[1]不详

出　　处：《Journal of Biomedical Science and Engineering》2011年第3期219-234,共16页生物医学工程（英文）

摘　　要：In order to study the aging changes of intramito-chondrial RNA synthesis of mouse adrenal cells, 10 groups of developing and aging mice, each consisting of 3 individuals, total 30, from fetal day 19 to postna-tal newborn at day 1, 3, 9, 14, adult at month 1, 2, 6 and senescent animals at month 12 (year 1) and 24 (year 2) were injected with 3H-uridine, an RNA pre-cursor, sacrificed 1 hr later and the adrenal tissues were fixed and processed for electron microscopic radioautography. On electron microscopic radio-autograms obtained from each animal, the number of mitochondria per cell, the number of labeled mito-chondria with 3H-uridine showing RNA synthesis per cell and the mitochondrial labeling index in each adreno-cortical cells, in 3 zones, as well as in each adreno-medullary cells, 2 types of cells in the medulla, the adrenalin cells and the noradrenalin cells, were calculated and the results in respective aging groups were compared with each others. The results demon-strated that the number of mitochondria in adreno-cortical cells in 3 zones, the zona glomerulosa, fasciculata and reticularis of respective mice at vari-ous ages increased from fetal day 19 to postnatal month 1 reaching the plateau from month 1 to 24 due to development and aging of animals, respectively, while the number of labeled mitochondria per cell and the labeling index of intramitochondrial RNA synthesis incorporating 3H-uridine increased from fetal day 19 to postnatal month 2, reaching the maxima and decreased slightly from month 6 to month 24. On the other hand, the number of mito-chondria per cell in the medulla increased from fetal day 19 to postnatal month 1 reaching the plateau from month 1 to 24, while the number of labeled mi-tochondria per cell and the labeling index of in-tramitochondrial RNA synthesis increased from fetal day 19 to postnatal day 14, reaching the maxima and decreased from month 1 to 24. From the results, it was demonstrated that the activity of intramitochno-drial RNA synthesis in both the cortical and me-dullarIn order to study the aging changes of intramito-chondrial RNA synthesis of mouse adrenal cells, 10 groups of developing and aging mice, each consisting of 3 individuals, total 30, from fetal day 19 to postna-tal newborn at day 1, 3, 9, 14, adult at month 1, 2, 6 and senescent animals at month 12 (year 1) and 24 (year 2) were injected with 3H-uridine, an RNA pre-cursor, sacrificed 1 hr later and the adrenal tissues were fixed and processed for electron microscopic radioautography. On electron microscopic radio-autograms obtained from each animal, the number of mitochondria per cell, the number of labeled mito-chondria with 3H-uridine showing RNA synthesis per cell and the mitochondrial labeling index in each adreno-cortical cells, in 3 zones, as well as in each adreno-medullary cells, 2 types of cells in the medulla, the adrenalin cells and the noradrenalin cells, were calculated and the results in respective aging groups were compared with each others. The results demon-strated that the number of mitochondria in adreno-cortical cells in 3 zones, the zona glomerulosa, fasciculata and reticularis of respective mice at vari-ous ages increased from fetal day 19 to postnatal month 1 reaching the plateau from month 1 to 24 due to development and aging of animals, respectively, while the number of labeled mitochondria per cell and the labeling index of intramitochondrial RNA synthesis incorporating 3H-uridine increased from fetal day 19 to postnatal month 2, reaching the maxima and decreased slightly from month 6 to month 24. On the other hand, the number of mito-chondria per cell in the medulla increased from fetal day 19 to postnatal month 1 reaching the plateau from month 1 to 24, while the number of labeled mi-tochondria per cell and the labeling index of in-tramitochondrial RNA synthesis increased from fetal day 19 to postnatal day 14, reaching the maxima and decreased from month 1 to 24. From the results, it was demonstrated that the activity of intramitochno-drial RNA synthesis in both the cortical and me-dullar

关 键 词：Mouse MITOCHONDRIA ADRENAL CORTEX and MEDULLA EM Radioautography RNA Synthesis 

分 类 号：R73[医药卫生—肿瘤]