title: Age-dependent changes in pyruvate uptake by nonsynaptic and synaptic mitochondria from rat brain.
abstract: Changes in the uptake of pyruvate by nonsynaptic and synaptic mitochondria from brains of young adult and old rats were investigated. An age-dependent decrease in State 3 respiration in the presence of pyruvate plus malate as substrate was observed in cerebral mitochondrial populations but not in liver mitochondria. Addition of exogenous cytochrome c to nonsynaptic and synaptic mitochondria enhanced the rate of State 3 respiration but the age-dependent decrease in State 3 respiration persisted in both types of mitochondria. A decrease in the uptake of pyruvate as measured by the inhibitor-stop and rapid centrifugation techniques was observed in both nonsynaptic and synaptic mitochondria from 24-month-old rats compared to 3-month-old rats. The results suggest that the decrease in the uptake of pyruvate may be one of the factors responsible for the observed reduction in State 3 respiration in the presence of pyruvate plus malate by both nonsynaptic and synaptic mitochondria from brains of senescent rats compared to young adults.
mesh_terms: D000375:Aging; D000818:Animals; D001921:Brain / Q000378:metabolism*; D003574:Cytochrome c Group / Q000378:metabolism; D066298:In Vitro Techniques; D008293:Malates / Q000378:metabolism; D008297:Male; D008928:Mitochondria / Q000378:metabolism*; D010101:Oxygen Consumption; D011773:Pyruvates / Q000378:metabolism*; D019289:Pyruvic Acid; D051381:Rats; D013569:Synapses / Q000378:metabolism
chemical_list: D003574:Cytochrome c Group; D008293:Malates; D011773:Pyruvates; C030298:malic acid; D019289:Pyruvic Acid