Open AccessReduced transcription of mitochondrial DNA in the senescent rat
Author(s) -
GADALETA Maria Nicola,
PETRUZZELLA Vittoria,
RENIS Marcella,
FRACASSO Flavio,
CANTATORE Palmiro
Publication year - 1990
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1990.tb15331.x
Subject(s) - mitochondrial dna , senescence , cytochrome c oxidase , biology , transcription (linguistics) , mitochondrion , dna , rna , messenger rna , carnitine , microbiology and biotechnology , gene , biochemistry , linguistics , philosophy
A quantitative study on the effect of senescence on mitochondrial DNA expression has been carried out by measuring the levels of the 12S rRNA and of the mRNA for the subunit I of cytochrome oxidase in several tissues of adult and senescent rats. The concentration of both RNA species/mitochondrial DNA molecule is significantly reduced in senescent brain and heart, as opposed to the respective adult tissues. No appreciable variation occurs in the liver. A 1‐h pretreatment with acetyl‐L‐carnitine brings back the level of senescent brain and heart transcripts to that of adult tissues. The same treatment of adult rats does not cause significant changes in mitochondrial RNA content. These results suggest that the age‐dependent impairment of both heavy‐strand mitochondrial DNA transcription units is related to altered environmental conditions which acetyl‐L‐carnitine, a substance which acts by stimulating, directly or indirectly, the energy metabolism, is able to remove.