Impairment of glutamate uptake and absence of alterations in the energy-transducing ability of old rat brain mitochondria.
The proton electrochemical gradient has been measured in old brain mitochondria isolated from 2- or 24-month-old rats with the use of different respiratory substrates. With succinate as substrate, neither the respiratory rate, membrane potential or delta pH varied with age, indicating that the dielectric strength of the mitochondrial membrane was unaltered in old animals. The ohmic behavior of the membrane was tested in experiments in which the respiratory rate was partially inhibited by malonate, and was found to be unchanged with age. When glutamate plus malate were used as substrates, the respiratory rate was substantially reduced, and a drastic decrease in glutamate uptake was observed in old rat brain mitochondria.
Vitorica
J
J
Clark
A
A
Machado
A
A
Satrústegui
J
J
D000375:Aging; D000818:Animals; D001921:Brain / Q000378:metabolism*; D004553:Electric Conductivity; D004734:Energy Metabolism; D005260:Female; D005971:Glutamates / Q000378:metabolism*; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D010101:Oxygen Consumption; D011522:Protons; D051381:Rats; D011919:Rats, Inbred Strains
D005971:Glutamates; D011522:Protons