Aberrant Histone Acetylation Promotes Mitochondrial Respiratory Suppression in the Brain of Alcoholic Rats

The effects of hypercapnia on cerebral electrical activity and mitochondrial oxidative phosphorylation were studied in the anesthetized neonatal dog by using the electrocorticogram (ECoG) and 31P-magnetic resonance spectroscopy. Three levels of hypercapnia with arterial PCO2 values of approximately 70, 100, and 140 Torr reduced the intracellular pH of the brain from 7.11 to 6.99, 6.87, and 6.76, respectively. These levels of hypercapnia also reduced ADP concentration ([ADP]) from 21.5 to 18.1, 14.8, and 12.9 microM as well as the average ECoG power output by 20, 30, and 40%. A Michaelis-Menten relationship for the mitochondrial respiratory enzymes was fitted with [ADP] and the change in the average ECoG. The result suggests that mitochondrial respiration is regulated by [ADP] and that the in vivo Michaelis-Menten constant for ADP was 21 microM, a value close to the in vitro value. The mitochondrial maximal reaction velocity was reduced by only 10% during hypercapnia and showed no relationship with the degree of acidosis, suggesting that mitochondrial respiratory enzymes are not responsible for the inhibition of the brain electrical activity.

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Mitochondrial Respiratory Chain Dysfunction in the Brain is not a Major Component of Increased Reactive Oxygen Species in Neural Mechanisms of Hypertension

The FASEB Journal ◽

10.1096/fasebj.20.4.a358-b ◽

2006 ◽

Vol 20 (4) ◽

Author(s):

Masatsugu Nozoe ◽

Yoshitaka Hirookka ◽

Yasuaki Koga ◽

Yoji Sagara ◽

Tomomi Ide ◽

...

Keyword(s):

Reactive Oxygen Species ◽

Respiratory Chain ◽

Reactive Oxygen ◽

Mitochondrial Respiratory Chain ◽

Neural Mechanisms ◽

Oxygen Species ◽

The Brain ◽

Mitochondrial Respiratory

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Mitochondrial respiratory chain activity in an animal model of mania induced by ouabain

Acta Neuropsychiatrica ◽

10.1111/j.1601-5215.2011.00543.x ◽

2011 ◽

Vol 23 (3) ◽

pp. 106-111 ◽

Cited By ~ 2

Author(s):

Tiago P. Freitas ◽

Gislaine T. Rezin ◽

Daiane B. Fraga ◽

Morgana Moretti ◽

Julia S. Vieira ◽

...

Keyword(s):

Animal Model ◽

Prefrontal Cortex ◽

Respiratory Chain ◽

Rebound Effect ◽

Mitochondrial Respiratory Chain ◽

Face Validity ◽

Mitochondrial Respiratory Chain Activity ◽

Respiratory Chain Activity ◽

The Brain ◽

Mitochondrial Respiratory

Objectives: Bipolar disorder (BD) is a mental illness associated with higher rates of suicide. The present study aims to investigate the brain mitochondrial respiratory chain activity in an animal model of mania induced by ouabain.Methods: Adult male Wistar rats received a single intracerebroventricular administration of ouabain (10−3 and 10−2 M) or vehicle. Locomotor activity was measured using the open field test. Mitochondrial respiratory chain activity was measured in the brain of rats 1 h and 7 days after ouabain administration.Results: Our results showed that spontaneous locomotion was increased 1 h and 7 days after ouabain administration. Complexes I, III and IV activities were increased in the prefrontal cortex, hippocampus and striatum immediately after the administration of ouabain, at the concentration of 10−3 and 10−2 M. Moreover, complex II activity was increased only in the prefrontal cortex at the concentration of 10−2 M. On the other hand, no significant alterations were observed in complex I activity 7 days after ouabain administration. However, an increase in complexes II, III and IV activities was observed only in the prefrontal cortex at the concentration of 10−2 M.Conclusion: Our findings suggest an increase in the activities of mitochondrial respiratory chain in this model of mania. A possible explanation is that these findings occur as a rebound effect trying to compensate for a decrease of ATP deprivation in BD. The present findings suggest that this model may present good face validity and a limitation in construct validity.

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