?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=RNA+Synthesis+in+the+Tracheal+Epithelial+Cells+of+Aging+Mice+as+Revealed+by+Electron+Microscopic+Radioautography+&rft.creator=Tetsuji+Nagata+%2C+Int+J+Cur+Sci+Res&rft.subject=JOURNALS&rft.description=For+the+purpose+of+studying+the+aging+changes+of+macromolecular+synthesis+in+the+tracheal+epithelial+cells+of+experimental+animals%2C+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%2C+a+precursor+for+RNA+synthesis%2C+sacrificed+and+the+tracheal+tissues+were+taken+out%2C+fixed+and+processed+for+light+and+electron+microscopic+radioautography.+On+many+radioautograms+the+localization+of+silver+grains+demonstrating+RNA+synthesis+in+tracheal+epithelial+cells+in+respective+aging+groups+were+analyzed+qualitatively+and+quantitatively.+The+number+of+mitochondria+per+cell%2C+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%2C+i.e.%2C+the+number+of+silver+grains+in+cell+nuclei%2C+cell+organelles%2C+changed+due+to+the+aging+of+animals.+The+number+of+mitochondria%2C+the+number+of+labeled+mitochondria+and+the+mitochondrial+labeling+index+labeled+with+silver+grains+were+counted+in+each+tracheal+epithelial+cell.+It+was+demonstrated+that+the+number+of+mitochondria+increased+from+embryonic+day+19+to+postnatal+newborn+day+1%2C+3%2C+9%2C+14%2C+adult+month+1%2C+2%2C+reaching+the+maximum+and+kept+plateau%2C+while+the+number+of+labeled+mitochondria+increased+from+embryonic+day+19+to+postnatal+adult+month+2%2C+reaching+the+maximum+but+the+labeling+indices+showing+RNA+synthesis+increased+from+embryonic+day+19+to+postnatal+newborn+day+14+and+adult+month+1+and+decreased+to+year+2%2C+indicating+the+aging+changes.+Based+upon+our+findings%2C+available+literature+on+macromolecular+synthesis+in+mitochondria+of+various+cells+are+reviewed.&rft.publisher=CurrentSciDirect+Publications&rft.date=2011-04-30&rft.type=Journal+(Paginated)&rft.type=PeerReviewed&rft.format=application%2Fpdf&rft.identifier=http%3A%2F%2Fcogprints.org%2F7303%2F1%2FRNA_Synthesis_in_the_Tracheal_Epithelial_Cells_of_Aging_Mice_as_Revealed_by_Electron_Microscopic_Radio.pdf&rft.identifier=++Tetsuji+Nagata+%2C+Int+J+Cur+Sci+Res++(2011)+RNA+Synthesis+in+the+Tracheal+Epithelial+Cells+of+Aging+Mice+as+Revealed+by+Electron+Microscopic+Radioautography.++%5BJournal+(Paginated)%5D+++++&rft.relation=http%3A%2F%2Fcogprints.org%2F7303%2F