Cytochrome aa3 depletion is the cause of the deficient mitochondrial respiration induced by chronic valproate administration

Ponchaut, Sylvie; Hoof, F. Van; Veitch, Keith

doi:10.1016/0006-2952(92)90590-f

Cited by 44 publications

(28 citation statements)

References 17 publications

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“…Thus, at most, the drug may hasten the onset of liver failure. Such an adverse effect would be plausible, since sodium valproate has been shown to inhibit cytochrome c oxidase in rat liver (28).…”

Section: Pathogenesis Of Mitochondrial Diseasementioning

confidence: 99%

Mitochondrial respiratory chain disorders and the liver

Morris

1999

Liver

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Mitochondrial respiratory chain disorders are an established cause of liver failure in early childhood but they are probably under-diagnosed, partly due to under-recognition and partly due to the difficulty of investigation. It is particularly important to look for mitochondrial disorders if the liver disease presents with hypoglycaemia and lactic acidaemia or if it is accompanied by neurological, muscle or renal tubular abnormalities. Respiratory chain defects have been demonstrated in a number of patients who die of liver failure following severe epilepsy; this includes at least some cases of Alpers syndrome or 'progressive neuronal degeneration of childhood'. In mitochondrial liver disease, histology usually shows steatosis, often accompanied by fibrosis, cholestasis and loss of hepatocytes. Unless the clinical picture suggests a particular syndrome, such as Pearson syndrome, biochemical assays and histochemistry should be the initial investigations. Ideally, investigations should be carried out on liver as well as more standard tissues, such as muscle, since defects can be tissue-specific. Nuclear defects and nitDNA point mutations are probably responsible for many cases of mitochondrial liver disease but, as yet, the only identified molecular abnormalities are mtDNA rearrangements and mtDNA depletion. Treatment of mitochondrial liver disease is unsatisfactory. If the disease is confined to the liver, transplantation may be appropriate but in several patients transplantation has been followed by the appearance of disease in other organs, particularly the I brain.Mitochondria are subcellular organelles whose primary role is the oxidation of fuels to produce energy. This process is accomplished by a series of enzymes known as the mitochondrial respiratory chain. Mitochondria are the site of many other metabolic pathways but the term 'mitochondrial disease' is generally used to refer to those conditions associated with respiratory chain defects. Since the oxidation of fuels is important for almost all cells, defects of the mitochondrial respiratory chain can cause disease in any organ of the body. Liver disease is a relatively common problem in respiratory chain disorders that present during infancy. These genetic disorders are the sub,ject of the current review. Secondary defects of tlhe respiratory chain caused, for example, by drugs or toxins, can also lead to liver disease but these disorders are only considered briefly in the section on pathogenesis, where key references are giiven. Mitochondrial biochemistryMany oxidative reactions occur within mitochondria, including the D-oxidation pathway for fatty acids, the oxidative decarboxylation of pyruvate by the pyruvate dehydrogenase complex and the oxidation of acetyl-CoA by the tricarboxylic acid cycle. These reactions all generate reduced cofactors, such as the reduced forms of flavin adenine dinucleotide (FADH2) and nicotinamide adenine dinucleotide (NADH). The mitochondrial respiratory chain couples the reoxidation of these cofactors to the for...

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Section: Pathogenesis Of Mitochondrial Diseasementioning

confidence: 99%

Mitochondrial respiratory chain disorders and the liver

Morris

1999

Liver

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“…Enhancement of glutamic acid decarboxylation and inhibition of GABA transamination play dual roles. In animal studies, VPA have been reported to cause seizure [13][14][15][16]. The mechanism of this paradoxical effect is not known.…”

Section: Discussionmentioning

confidence: 99%

“…Altrup et al [13] reported that VPA changes the structure of the mitochondrial membrane, and Chabrol et al [14] demonstrated that VPA alters the activity of cytochrome c oxidase, a mitochondrial enzyme. Furthermore, measurements of the respiratory enzyme activities in even intact mitochondria of patients with MELAS, revealed that more than a half have associated with some degree of complex I, or complexes I and IV deficiency [13][14][15][16][17]. Therefore, we propose that in patients with mitochondrial diseases such as MELAS, a defective oxidative and phosphorylation (OX-PHOS) due to complex I or complex IV or both might predispose the patient to the unfavorable pharmacological effects of VPA on the mitochondrial machinery toward the paradoxical epileptogenicity.…”

Section: Discussionmentioning

confidence: 99%

“…Other supportive evidence gives clue to the explaination of this paradoxical cellular event. First, the papers by Ponchaut et al [15,16] demonstrated that the activity of complex IV of the respiratory chain is jeopardized by VPA. Second, Lam et al [17] suggested that there is an inborn error of mitochondrial system in patients whose seizures worsen by use of VPA.…”

Section: Discussionmentioning

confidence: 99%

“…A pre-existing hepatic mitochondrial dysfunction in MELAS per se may also contribute to a decrease in the capacity of hepatic elimination of VPA and its metabolite. The toxicity of accumulated VPA and its metabolites in turn accelerates the development of the mitochondrial "encephalopathy", changes of the mitochondrial membrane stability, and thus the paroxysmal depolarization shift (PDS) [13], and the subsequent seizures [12][13][14][15][16][17]. Finally, the threshold of PDS may be greatly altered and reduced by the regional brain acidic milleau (elevated H + concentration) associated with lactic acidosis.…”

Section: Discussionmentioning

confidence: 99%

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Paradoxical effect of sodium valproate that aggravates epilepsy of MELAS in a patient with A3243G mutation of the mitochondrial DNA

2007

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AbstractEpilepsy is an associated feature of patients with the syndrome of mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS). A substitution at nucleotide position 3243 A>G of the mitochondrial DNA is the most common mutation encountered both in Caucasians and in Chinese/Taiwanese. We herein report a 38-year-old man with A3243G mutation of the mitochondrial DNA whom developed MELAS. The manifestation of his focal motor epilepsy was aggravated by use of sodium valproate (VPA). The mechanism of this paradoxical effect is proposed.

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Mitochondrial Dysfunction in Drug‐Induced Liver Injury

Borgne‐Sanchez

Fromenty

2018

Mitochondrial Dysfunction Caused by Drugs and Environmental Toxicants

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Cytochrome aa3 depletion is the cause of the deficient mitochondrial respiration induced by chronic valproate administration

Cited by 44 publications

References 17 publications

Mitochondrial respiratory chain disorders and the liver

Mitochondrial respiratory chain disorders and the liver

Paradoxical effect of sodium valproate that aggravates epilepsy of MELAS in a patient with A3243G mutation of the mitochondrial DNA

Mitochondrial Dysfunction in Drug‐Induced Liver Injury

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