Age-related modifications of cytochrome C oxidase activity in discrete brain regions

• Published in: Mechanisms of ageing and development Vol. 55; no. 2; p. 171
• Main Authors: Curti, D, Giangare, M C, Redolfi, M E, Fugaccia, I, Benzi, G
• Format: Journal Article
• Language: English
• Published: Ireland 01-08-1990
• Subjects: Age Factors; Aging - metabolism; Animals; Cell Fractionation; Cerebral Cortex - enzymology; Cerebral Cortex - metabolism; Electron Transport Complex IV - metabolism; Male; Mitochondria - enzymology; Mitochondria - metabolism; Osmolar Concentration; Rats; Rats, Inbred Strains; Synaptosomes - enzymology; Synaptosomes - metabolism
• ISSN: 0047-6374
• DOI: 10.1016/0047-6374(90)90024-A

The apparent Km for cytochrome c of cytochrome oxidase does not change but the Vmax decreases in synaptosomes and non-synaptic mitochondria isolated from the cerebral cortex as a whole of 30-month-old rats compared with 4-month-old ones. When the subcellular organelles are submitted to stressful conditions, namely incubation in media of altered osmolality, the percentage of cytochrome oxidase activity released is much higher in senescent rats. The activity of cytochrome oxidase evaluated in non-synaptic mitochondria and synaptosomes isolated from cortical and subcortical regions and cerebellum of rats aged 4 and 30 months shows a highly significant decrease (P less than 0.001) in the parietotemporal cortex of senescent rats (both in non-synaptic mitochondria and synaptosomes) and in the cerebellum (in synaptosomes).