Progressive decrease of cerebral cytochrome C oxidase activity in sparse-fur mice: role of acetyl-L-carnitine in restoring the ammonia-induced cerebral energy depletion.

K V Rao; Y R Mawal; I A Qureshi

doi:10.1016/s0304-3940(97)13476-0

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PubMed · 9086462

Progressive decrease of cerebral cytochrome C oxidase activity in sparse-fur mice: role of acetyl-L-carnitine in restoring the ammonia-induced cerebral energy depletion.

K V Rao·Y R Mawal·I A Qureshi

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Abstract

Sparse-fur (spf) mice with a deficiency of hepatic ornithine transcarbamylase (OTC) are congenitally hyperammonemic, showing elevated cerebral ammonia and glutamine and depleted levels of energy metabolites. This mouse disorder is akin to the human OTC deficiency, in which neuronal loss and Alzheimer's type II astrocytosis is reported. Reduced cytochrome C oxidase (COX) activity is characteristic of neurodegeneration in Alzheimer's type disorders. We have studied the causal relationship between cerebral COX activity and energy depletion in spf mice. Our results indicate a progressive decrease in the COX activity in various brain regions in spf mice, up to 40 weeks of age, which severely effected the cerebral levels of various energy metabolites. A quantitative estimation of cerebral COX subunit I mRNA also showed a tendency to decrease in spf mice. Short-term acetyl L-carnitine (ALCAR) treatment restored these abnormalities. Our study points out that: (a) ammonia-induced alterations in the cerebral reducing equivalents could cause a decrease in COX activity and its mRNA expression, and (b) ALCAR administration could normalize the cerebral energy metabolism and induce COX mRNA expression and activity.

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Acetylcarnitine Ammonia Animals Brain Electron Transport Complex IV Energy Metabolism Female Male Mice Mice, Mutant Strains Mitochondria Nerve Degeneration Nootropic Agents Ornithine Carbamoyltransferase Ornithine Carbamoyltransferase Deficiency Disease RNA, Messenger Journal Article Research Support, Non-U.S. Gov't

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K V Rao, Y R Mawal, I A Qureshi. 1997-03-14. Progressive decrease of cerebral cytochrome C oxidase activity in sparse-fur mice: role of acetyl-L-carnitine in restoring the ammonia-induced cerebral energy depletion.. https://doi.org/10.1016/s0304-3940(97)13476-0

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