Reduced synthesis of mtRNA in isolated mitochondria of senescent rat brain.
A system for studying RNA synthesis in isolated mitochondria from rat brain was set up to investigate the mechanisms responsible for the age-dependent reduction of mtRNA content. In the presence of an appropriate incubation buffer both synaptic and non-synaptic mitochondria from cerebral hemispheres were able to synthesize and process mtRNA in a way quantitatively and qualitatively similar to the in vivo transcription. The comparison of the electrophoretic pattern of mtRNAs synthesized by adult and senescent rat showed, in the senescent rat, a 50% reduction in the mtRNA synthesis rate relative to the adult value. This indicates that the age-dependent decrease of the mtRNA content is linked to a lower efficiency of the mt transcription.
Fernandez-Silva
P
P
Dipartimento di Biochimica e Biologia Molecolare, Università di Bari, Italy.
Petruzzella
V
V
Fracasso
F
F
Gadaleta
M N
MN
Cantatore
P
P
D000375:Aging / Q000235:genetics*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D003720:Densitometry; D008297:Male; D012313:RNA / Q000096:biosynthesis*; D000077278:RNA, Mitochondrial; D051381:Rats; D011919:Rats, Inbred Strains; D014158:Transcription, Genetic
D000077278:RNA, Mitochondrial; D012313:RNA