Energy Metabolism in Rat Brain: Inhibition of Pyruvate Decarboxylation by 3-Hydroxybutyrate in Neonatal Mitochondria
| Autor: | R. F. G. Booth, John B. Clark |
|---|---|
| Rok vydání: | 1981 |
| Předmět: |
Male
Pyruvate decarboxylation Aging Pyruvate dehydrogenase kinase Hydroxybutyrates Pyruvate Dehydrogenase Complex Mitochondrion Biology Biochemistry Cellular and Molecular Neuroscience chemistry.chemical_compound Pyruvic Acid Animals Pyruvates Incubation 3-Hydroxybutyric Acid Acetyl-CoA Brain Rat brain Pyruvate dehydrogenase complex Mitochondria Rats Animals Newborn chemistry Female NAD+ kinase Synaptosomes |
| Zdroj: | Journal of Neurochemistry. 37:179-185 |
| ISSN: | 1471-4159 0022-3042 |
| DOI: | 10.1111/j.1471-4159.1981.tb05306.x |
| Popis: | The effect of 3-hydroxybutyrate on pyruvate decarboxylation by neonatal rat brain mitochondria and synaptosomes was investigated. The rate of [1-14C]pyruvate decarboxylation (1 mM final concentration) by brain synaptosomes derived from 8-day-old rats was inhibited by 10% in the presence of 2 mM-D,L-3-hydroxybutyrate and by more than 20% in the presence of 20 mM D,L-3-hydroxybutyrate. The presence of 2 mM-D,L-3-hydroxybutyrate did not affect the rate of [1-14C]pyruvate decarboxylation (1 mM final concentration) by brain mitochondria; however, at a concentration of 20 mM-D,L-3-hydroxybutyrate, a marked inhibition was seen in preparations from both 8-hydroxybutyrate, a marked inhibition was seen in preparations from both 8-day-old (35% inhibition) and 21-day-old (24% inhibition) but not in those from adult rats. Although the presence of 100 mM-K+ in the incubation medium stimulated the rate of pyruvate decarboxylation by approximately 50% compared with the rate in presence of 1 mM-K+, the presence of 20 mM-D,L-3-hydroxybutyrate still caused a marked inhibition in both media (1 and 100 mM-K+). The presence of 20 mM-D,L-3-hydroxybutyrate during the incubation caused an approximately 20% decrease in the level of the active form of the pyruvate dehydrogenase complex in brain mitochondria from 8-day-old rats. The concentrations of ATP, ADP, NAD+, NADH, acetyl CoA, and CoA were measured in brain mitochondria from 8-day-old rats incubated in the presence of 1 mM-pyruvate alone or 1 mM-pyruvate plus 20 mM-D,L-3-hydroxybutyrate. Neither the APT/ADP nor the NADH/NAD+ ratio showed significant changes. The acetyl CoA/CoA ratio was significantly increased by more than twofold in the presence of 3-hydroxybutyrate. The possible mechanisms and physiological significance of 3-hydroxybutyrate inhibition of pyruvate decarboxylation in neonatal rat brain rat mitochondria are discussed. |
| Databáze: | OpenAIRE |
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