Electron Microscopic Radioautography Research Articles

Original Article: Electron Microscopic Radioautographic Studies on the RNA Synthesis in the Colonic Epithelial Cells of Aging Mice

For the purpose of studying the aging changes of macromolecular synthesis in the colonic cells of experimental animals, we studied 10 groups of aging mice during aging from fetal day 19 to postnatal month 24. They were injected with 3 H-uridine, a precursor for RNA synthesis, sacrificed and the colonic tissues were taken out, fixed and processed for light and electron microscopic radioautography. On many radioautograms the localization of silver grains demonstrating RNA synthesis in colonic epithelial cells in respective aging groups were analyzed qualitatively. The number of mitochondria per cell, the number of labeled mitochondria with silver grains in each cell in respective aging groups were analyzed qualitatively and quantitatively in relation to the aging of animals. The results revealed that the RNA synthesis as expressed by the number of silver grains in cell nuclei, cell organelles, changed with the aging of animals. It was demonstrated that the number of mitochondria increased from embryonic day 19 to postnatal newborn day 1, 3, 7, 14, adult month 1 and 2, reaching the maximum, then decreased to senile year 1 to 2. On the other hand, the number of labeled mitochondria showing RNA synthesis at various ages increased from embryonic day 19 to postnatal newborn day 1, 3, 7, 14, adult month 1 and 2, reaching the maximum and decreased slightly to senile month 6 to senile year 1 and 2. To the contrary, the labeling index increased from embryonic day 19 to postnatal day 1, 2 and 3, then decreased to day 14 and month 1, and increased again to month 6, 12 and month 24, indicating the aging changes. These results demonstrated that intramitochondrial RNA synthesis in the colonic epithelial cells increased, then decreased and again increased due to aging of individual animals depending upon the cellular activities at respective aging stages. Based upon our findings, available literatures on macromolecular synthesis in mitochondria of various cells are reviewed.

RNA Synthesis in the Pancreatic Acinar Cells of Aging Mice as Revealed by Electron Microscopic Radioautography

For the purpose of studying the aging changes of macromolecular synthesis in the pancreatic acinar cells of experimental animals, we studied 10 groups of aging mice during development and aging from fetal day 19 to postnatal month 24. They were injected with 3H-uridine, a precursor for RNA synthesis, sacrificed and the pancreatic tissues were taken out, fixed and processed for light and electron microscopic radioautography. On many radioautograms the localization of silver grains demonstrating RNA synthesis in pancreatic acinar cells in respective aging groups were analyzed qualitatively. The number of mitochondria per cell, the number of labeled mitochondria with silver grains and the number of silver grains in each cell in respective aging groups were analyzed quantitatively in relation to the aging of animals. The results revealed that the RNA synthetic activity as expressed by the incorporations of RNA precursor, i.e., the number of silver grains in cell nuclei, cell organelles, changed due to the aging of animals. The number of mitochondria, the number of labeled mitochondria and the mitochondrial labeling index labeled with silver grains were counted in each pancreatic acinar cell. It was demonstrated that the number of mitochondria, the number of labeled mitochondria and the labeling indices showing RNA synthesis at various ages increased from embryonic day 19 to postnatal newborn day 1, 3, 9, 14, adult month 1, 2 and 6, reaching the maxima, then decreased to senile stage at postnatal year 1 to 2, indicating the aging changes. Based upon our findings, available literature on macromolecular synthesis in mitochondria of various cells are reviewed.

自著とその周辺 Tetsuji Nagata : Electron microscopic radioautography and Its Application to DNA, RNA and Protein Synthesis in Mitochondria of Various Animal Organs. In, Microscopy : Science, Technology and Education.

自著とその周辺 Tetsuji Nagata : Electron microscopic radioautography and Its Application to DNA, RNA and Protein Synthesis in Mitochondria of Various Animal Organs. In, Microscopy : Science, Technology and Education.

The dynamics of proliferation and differentiation of osteogenic cells under supportive unloading

With the use of radioactive marker of DNA synthesis--3H-thymidine we have studied the dynamics, peculiarities of proliferation and differentiation of osteogenic cells under hind limb unloading of white rats ("tail suspension" method at an angle 35 degrees) during 28 days. The 3H-thymidine was administered at a single dose at the end of the experiment, the biosamples were taken from femoral bones in 1, 48, 96 hr. Light and electron-microscopic radioautography with 3H-thymidine (in 1 hour) have shown, that basic fraction of DNA synthesizing cells in the zones of adaptive remodelling of bone tissue is represented by little-differentiated perivascular cells (that include osteogenic cell precursors). A tendency for a decrease of a labelling index in the 3H-thymidine osteogenic cells on metaphyseal bone trabeculae under hind limb unloading has been established. The dynamics of labelled cells during various time intervals after 3H-thymidine injection testifies to a delay in the differentiation precursors in osteoblasts and their transformation to osteocytes in experiment animals. The obtained data have shown that a long-term supportive unloading leads to lowering the intensity of osteogenetic processes in long bones and reducing bone mass.

Electron Microscopic Radioautographic Study on the Protein Synthesis in the Pancreas of Aging Mice With Special Reference to Mitochondria.

BackgroundThe purpose of this study was to investigate the aging changes of macromolecular synthesis in animal cells.MethodsWe studied 10 groups of mice during development aged from fetal day 19 to postnatal month 24. They were injected with 3H-leucine, a precursor for protein synthesis, sacrificed and the pancreatic tissues were taken out, fixed and processed for light and electron microscopic radioautography. On many radioautograms the localization of silver grains demonstrating protein synthesis in pancreatic acinar cells in respective aging groups were first analyzed qualitatively. Then the number of silver grains and the number of cell organelles in each cell in respective aging groups were analyzed quantitatively in relation to the aging of animals. The number of mitochondria, the number of labeled mitochondria and the mitochondrial labeling index labeled with silver grains were counted in each pancreatic acinar cell.Results and ConclusionsThe number of silver grains in cell nuclei and cell organelles changed with the aging of animals. The number of mitochondria, the number of labeled mitochondria and the labeling indices showing protein synthesis at various ages increased from embryonic day 19 to postnatal newborn day 1, 3, 7, 14, to young adult month 1, and 2, reaching the maxima, then decreased at old adult month 6 and senile year 1 to 2, indicating the aging changes.

自著とその周辺 Tetsuji Nagata : Macromolecular synthesis in the livers of aging mice as revealed by electron microscopic radioautography. In, Progress in Histochemistry and Cytochemistry. Vol. 45, No. 1

自著とその周辺 Tetsuji Nagata : Macromolecular synthesis in the livers of aging mice as revealed by electron microscopic radioautography. In, Progress in Histochemistry and Cytochemistry. Vol. 45, No. 1

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

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-dullary cells in developing and aging mice adrenals changed due to aging of individual animals.

Electron Microscopic Radioautographic Studies on Macromolecular Synthesis in Mitochondria of Animal Cells in Aging

Study aging changes of intramitochondrial DNA, RNA, protein synthesis of mouse organs during the development and aging, 30 groups of developing and aging mice (3 individuals each), from fetal day 19 to postnatal newborn at day 1, 3, 9, 14 and adult at month 1, 2, 6, 12 to 24, were injected with either 3H-thymidine, 3H-uriidine, or 3H-leucine, sacrificed 1 h later and liver, adrenal, lung and testis tissues observed by electron microscopic radioautography. Accordinlgy, numbers of mitochondria per cell profile area, numbers of labeled mitochondria and the mitochondrial labeling index labeled with 3H-labeled precursors showing DNA, RNA, protein synthesis in these cells (hepatocytes, 3 zones of the adrenal cortices - zona glomerulosa, fasciculata and reticularis -, adrenal medullary cells, pulmonary cells and testis cells) were counted per cells and compared among the respective developing and aging groups. The numbers of mitochondria in these cells increased from fetal day 19 to postnatal month 1 and 2. However, the numbers of labeled mitochondria and the labeling indices of intramitochondrial DNA, RNA, protein syntheses incorporating the 3H-labeled precursors in the described tissue cells increased from fetal day 19 to postnatal month 1 and decreased to month 24. These data support that the activity of intramitochnodrial DNA, RNA, protein syntheses in cells of these tissues increased and decreased by development and aging in mice. The intramitochondrial DNA, RNA and protein syntheses in some other organs were also reviewed and discussed

Electron Microscopic Radioautographic Study on DNA Synthesis of Mitochondria in Adrenal Medullary Cells of Aging Mice~!2009-08-12~!2009-09-17~!2009-12-24~!

For the purpose of clarifying the aging changes of DNA synthesis of mouse mitochondria in adrenal medullary cells, 10 groups of aging mice, each consisting of 3 individuals, total 30, from fetal day 19 to postnatal newborn at day 1, 3, 9, 14, adult at month 1, 2, 6, 12 and 24, were injected with 3H-thymidine, sacrificed 1 hr later and the adrenal tissues were fixed and processed for electron microscopic radioautography. On electron microscopic radioautograms obtained from each animal, number of mitochondria and the number of labeled mitochondria labeled with silver grains due to 3H-thymidine showing DNA synthesis in each adrenalin cell and noradrenalin cell were counted and the results of labeling indices in respective developing groups were compared respectively.

自著とその周辺 Tetsuji Nagata : Chapter 22. Sexual difference between the macromolecular synthesis of hepatocyte mitochondria in male and female mice in aging as revealed by electron microscopic radioautography. pp. 461-487, In, Women and Aging : New Research

自著とその周辺 Tetsuji Nagata : Chapter 22. Sexual difference between the macromolecular synthesis of hepatocyte mitochondria in male and female mice in aging as revealed by electron microscopic radioautography. pp. 461-487, In, Women and Aging : New Research

Studies on mitochondrial macromolecular syntheses in various organs of aging animals labeled with 3H-precursors as revealed by electron microscopic radioautography

In order to study the aging changes of intramitochondrial macromolecular synthesis in various organs of aging animals during the development and aging, 10 groups of developing and aging mice, each consisting of 3 individuals, total 30, from fetal day 19 to postnatal newborn at day 1, 3, 9, 14 and adult at month 1, 2, 6, 12 to 24 were injected with 3H-thymidine a DNA precurson, another 10 groups consisting of 3 individuals, total 30, were injected with 3H-uridine a RNA precursor, and another 10 groups of 30 individuals were injected with 3H-leucine a protein precursor, total 90 individuals. Then, all the animals were sacrificed 1 hr after the injections and the liver tissues, the lung tissues, the kidney tissues, the testis and ovary tissues, the adrenal tissues were taken out, fixed and processed for electron microscopic radioautography. On electron microscopic radioautograms obtained from each animal, ten photographs in respective groups, numbers of mitochondria per cell profile area, numbers of labeled mitochondria per cell and the mitochondrial labeling index (LI) labeled with 3H-thymidine showing DNA synthesis, LI labeled with 3H-uridine showing RNA synthesis, and LI labeled with 3H-leucine showing protein synthesis, in various organs, were counted and the results in various organs in respective aging groups were compared, respectively. From the results, it was demonstrated that the numbers of mitochondria in hepatocytes as well as in 3 zones of the adrenal cortex, the zona glomerulosa, fasciculata and reticularis of mice at various ages increased from fetal day 19 to postnatal month 1 due to development and aging of animals. On the other hand, the numbers of labeled mitochondria and the labeling indices of intramitochondrial DNA syntheses incorporating 3H-thymidine in hepatocytes and 3 zones of cortical cells increased from fetal day 19 to postnatal month 1 and decreased to month 24. The numbers of labeled mitochondria and the labeling indices of intramitochondrial RNA syntheses incorporating 3H-uridine in hepatocytes and 3 zones of cortical cells increased from fetal day 19 to postnatal month 1 and decreased to month 24. The numbers of labeled mitochondria and the labeling indices of intramitochondrial RNA syntheses incorporating 3H-uridine in hepatocytes and 3 ones of cortical cells increased from fetal day 19 to postnatal month 1 and decreased to month 24. Moreover, some other organs such as the lung and the testis were also review and discussed. From the results, it was shown that the activity of intramitochnodrial DNA synthesis, RNA synthesis, and protein synthesis in hepatocytes, adrenal cortical cells, pulmonary cells and testicular cells in developing and aging mice as well as some other organs increased and decreased due to development and aging.

Recent Studies on Macromolecular Synthesis Labeled with 3H-Thymidine in Various Organs as Revealed by Electron Microscopic Radioautography

In order to study the aging changes of intramitochondrial DNA synthesis of mouse adrenal cells during the development, 10 groups of developing mice, each consisting of 3 individuals, total 30, from fetal day 19 to postnatal newborn at day 1, 3, 9, 14 and adult at month 1, 2, 6, 12 and 24 were injected with 3H-thymidine, sacrificed 1 hr later and the adrenal tissues were processed for electron microscopic radioautography. On electron microscopic radioautograms obtained from each animal, numbers of mitochondria per cell, numbers of labeled mitochondria and the mitochondrial labeling index labeled with 3H-thymidine showing DNA synthesis in each adrenal cortical cell, in 3 zones, as well as adrenal medullary cells were counted and the results in respective groups were compared, respectively. From the results, it was demonstrated that the numbers of mitochondria in 3 zones, the zona glomerulosa, fasciculata and reticularis of mice at various ages as well as the numbers of mitochondria in 2 types of medullary cells, adrenalin cells and noradrenalin cells, increased from fetal day 19 to postnatal month 1 due to development and aging of animals. On the other hand, the numbers of labeled mitochondria and the labeling indices of intramitochondrial DNA syntheses incorporating 3H-thymidine in 3 zones of cortical cells increased from fetal day 19 to postnatal month 1, while the numbers of labeled mitochondria and the labeling indices of intramitochondrial DNA syntheses in medullary cells, both the adrenalin and the noradrenalin cells incorporating 3H-thymidine increased from fetal day 19 to postnatal day 14 and decreased to month 1. From the results, it was shown that the activity of intramitochnodrial DNA synthesis in both the adrenal cortical and the medullary cells in developing mice changed due to development and aging but the cortical cells and the medullary cells were a little different from each other. The intramitochondrial DNA syntheses in some other organs were also reviewed and discussed. Keywords: Mouse adrenal cortex, medulla, electron microscopic radioautography, DNA synthesis, mitochondria, development, aging, hepatocyte

Ultrastructural study of the effect of TNT on callus cells and cells of intact plants of Yucca gloriosa L.

Intracellular distribution of assimilated 2,4,6-trinitrotoluene (TNT) in callus cells, flower buds, and leaves of intact Yucca gloriosa L. plants with the use of electron microscopy radioautography was carried out. The radiotracer was detected in vacuoles, plastids, mitochondria, endoplasmic reticulum, and cytoplasm. It was found that TNT incorporation in the vacuoles of dedifferentiated callus cells was higher compared to cells from intact plant. Therefore, the ultrastructural continuity of differentiated cells is less damaged.

自著とその周辺 Tetsuji Nagata : Chapter VI. Protein synthesis in hepatocytes of mice as revealed by electron microscopic radioautography. pp. 133-161, In, Protein Biosynthesis

自著とその周辺 Tetsuji Nagata : Chapter VI. Protein synthesis in hepatocytes of mice as revealed by electron microscopic radioautography. pp. 133-161, In, Protein Biosynthesis

Subcellular location of horseradish peroxidase in horseradish leaves treated with La(III), Ce(III) and Tb(III)

The agricultural application of rare-earth elements (REEs) would promote REEs inevitably to enter in the environment and then to threaten the environmental safety and human health. Therefore, the distribution of the REEs ion, 141Ce(III) and effects of La(III), Ce(III) and Tb(III) on the distribution of horseradish peroxidase (HRP) in horseradish mesophyll cells were investigated with electron microscopic radioautography and transmission electron microscopic cytochemistry. It was found for the first time that REEs ions can enter into the mesophyll cells, deposit in both extra and intra-cellular. Compared to the normal condition, after the horseradish leaves treated with La(III) or Tb(III), HRP located on the tonoplast is decreased and HRP is mainly located on the cell wall, while HRP is mainly located on the plasma membrane after the horseradish leaves were treated with Ce(III). This also indicated that REEs ions may regulate the plant growth through changing the distribution of enzymes.

自著とその周辺 Tetsuji Nagata : Macromolecular synthesis in hepatocyte mitochondria of aging mice as revealed by electron microscopic radioautography I. Nucleic Acid Synthesis. p. 245-258 II. Protein Synthesis. p. 259-271 In, Modern Research and Educational Topics in Microscopy

自著とその周辺 Tetsuji Nagata : Macromolecular synthesis in hepatocyte mitochondria of aging mice as revealed by electron microscopic radioautography I. Nucleic Acid Synthesis. p. 245-258 II. Protein Synthesis. p. 259-271 In, Modern Research and Educational Topics in Microscopy

Electron Microscopic Radioautographic Study on Mitochondrial DNA Synthesis in Adrenal Cortical Cells of Developing and Aging Mice

In order to study the aging changes of intramitochondrial DNA synthesis of mouse adrenal cortical cells, eight groups of developing mice, each consisting of three individuals (total 24), from fetal day 19 to postnatal newborn at days 1, 3, 9, 14, to adult at months 1, 2, and 6, were injected with 3H-thymidine, sacrificed 1 h later, and the adrenal tissues were fixed and processed for electron microscopic (EM) radioautography. On EM radioautograms obtained from each animal, the number of mitochondria and the mitochondrial labeling index labeled with 3H-thymidine showing DNA synthesis in each adrenal cortical cell, in three zones, were counted and the results in respective developing groups were compared. From the results, it was demonstrated that the numbers of mitochondria in the three zones, the zona glomerulosa, fasciculata, and reticularis, of mice at various ages increased from fetal day 19 to postnatal month 6 due to development and aging of animals, respectively, while the number of labeled mitochondria and the labeling index of intramitochondrial DNA syntheses incorporating 3H-thymidine increased from fetal day 19 to postnatal month 2, reaching the maxima, and decreased to month 6. It was shown that the activity of intramitochondrial DNA synthesis in the adrenal cortical cells in developing and aging mice changed due to aging.

Aging changes of Macromolecular Synthesis in the Avian and Mammalian Eyes as Revealed by Microscopic Radioautography

Nagata T. Aging Changes of Macromolecular Synthesis in the Avian and Mammalian Eyes as Revealed by Microscopic Radioautography. ARBS Annu Rev Biomed Sci 2006;8:33-67. In order to elucidate the aging changes of macromolecular synthesis such as DNA, RNA, proteins and glucides in various organ systems of experimental animals and men, we have studied various organs such as the skeletal, muscular, digestive, respiratory, urinary, reproductive, endocrine, circulatory, nervous and sensory systems after incorporations with radiolabeled macromolecular precursors by light and electron microscopic radioautography. This review deals with the results obtained from the avian and mammalian eyeballs. The experimental animals mainly used were chicken embryos during incubation for 1-7 days and strain mice at various aging groups from embryo to postnatal juvenile 1 and 3 days, 1 and 2 weeks, mature 1, 2 and 6 months up to 1 and 2 years at senescent stages. The animals were injected with such macromolecular precursors as 3 H-thymidine for DNA, 3 H-uridine for RNA, 3 H-amino acids for proteins, 3 H-glucose, 3 H-glucosamine and 35 S-sulfate for glucides. The results demonstrated that these precursors were incorporated into various ocular cells and tissues at various aging groups from perinatal to juvenile, mature and senescent stages showing specific patterns of macromolecular synthesis. It is concluded that the difference of macromolecular syntheses during development and aging changes were demonstrated. © by Sao Paulo State University - ISSN 1806-8774

Electron Microscopic Radioautographic Study on Protein Synthesis in Mitochondria of Binucleate Hepatocytes of Aging Mice

In order to study the aging changes of intramitochondrial protein synthesis in mouse hepatocytes, 10 groups of aging mice, each consisting of three individuals, total 30, from fetal day 19 to postnatal year 2, were injected with 3H-leucine, a protein precursor, sacrificed 1 h later, and the liver tissues processed for electron microscopic radioautography. On electron microscopic radioautograms obtained from each animal, the numbers of mitochondria, the numbers of labeled mitochondria, and the mitochondrial labeling index labeled with 3H-leucine that showed protein synthesis in each hepatocyte, both mononucleate and binucleate cells, were counted and the averages in respective aging groups were compared. From the results, it was demonstrated that the numbers of mitochondria, the numbers of labeled mitochondria, and the labeling indices of intramitochondrial protein syntheses in both mononucleate and binucleate hepatocytes of mice at various ages increased due to development of animals. The numbers of mitochondria, the numbers of labeled mitochondria, and the labeling indices of intramitochondrial protein synthesis in binucleate hepatocytes were more than those of mononucleate hepatocytes at the same aging stages.

Electron Microscopic Radioautographic Study on Protein Synthesis in Hepatocyte Mitochondria of Aging Mice

For the purpose of studying the aging changes of intramitochondrial protein synthesis in mouse hepatocytes, 10 groups of aging mice, each consisting of 3 individuals (total 30), from fetal day 19 to postnatal month 24, were injected during development with 3H-leucine, a protein precursor, sacrificed 1 h later, and the liver tissues processed for electron microscopic (EM) radioautography. On EM radioautograms obtained from each animal, the number of mitochondria, the number of labeled mitochondria, and the mitochondrial labeling index labeled with silver grains due to H-leucine showing protein synthesis in each mononucleate hepatocytes were counted and the averages in respective aging groups were compared. From the results, it was demonstrated that the numbers of mitochondria, the numbers of labeled mitochondria, and the labeling indices of intramitochondrial protein syntheses in mononucleate hepatocytes of mice at various ages from embryonic day 19 to postnatal month 24 increased and decreased due to development and aging of animals.