Electron microscopic radioautographic study of RNA synthesis in hepatocyte mitochondria of aging mouse

✍ Scribed by Tetsuji Nagata; Hongjun Ma

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 547 KB
• Volume: 67
• Category: Article
• ISSN: 1059-910X
• DOI: 10.1002/jemt.20183

✦ Synopsis

In order to study the aging changes of intramitochondrial RNA synthesis in mouse hepatocytes, 10 groups of aging mice, each consisting of three individuals (total 30) from fetal day 19 to postnatal month 24 were injected with 3H-uridine, an RNA precursor, sacrificed 1 hour later, and the liver tissues processed for electron microscopic radioautography. On EM radioautograms obtained from each animal the number of mitochondria, the number of labeled mitochondria, and the mitochondrial labeling index labeled with 3H-uridine showing RNA synthesis in each hepatocytes, 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 RNA syntheses in both mononucleate and binucleate hepatocytes of mice at various ages increased and decreased according to the age of the animals.