Uncoupling, metabolic inhibition and induction of mitochondrial permeability transition in rat liver mitochondria caused by the major long-chain hydroxyl monocarboxylic fatty acids accumulating in LCHAD deficiency.

Patients with long-chain 3-hydroxy-acyl-CoA dehydrogenase (LCHAD) deficiency commonly present liver dysfunction whose pathogenesis is unknown. We studied the effects of long-chain 3-hydroxylated fatty acids (LCHFA) that accumulate in LCHAD deficiency on liver bioenergetics using mitochondrial preparations from young rats. We provide strong evidence that 3-hydroxytetradecanoic (3HTA) and 3-hydroxypalmitic (3HPA) acids, the monocarboxylic acids that are found at the highest tissue concentrations in this disorder, act as metabolic inhibitors and uncouplers of oxidative phosphorylation.

Ornithine In Vivo Administration Disrupts Redox Homeostasis and Decreases Synaptic Na(+), K (+)-ATPase Activity in Cerebellum of Adolescent Rats: Implications for the Pathogenesis of Hyperornithinemia-Hyperammonemia-Homocitrullinuria (HHH) Syndrome.

Hyperornithinemia-hyperammonemia-homocitrullinuria (HHH) syndrome is an inborn error of metabolism caused by a defect in the transport of ornithine (Orn) into mitochondrial matrix leading to accumulation of Orn, homocitrulline (Hcit), and ammonia. Affected patients present a variable clinical symptomatology, frequently associated with cerebellar symptoms whose pathogenesis is poorly known. Although in vitro studies reported induction of oxidative stress by the metabolites accumulating in HHH syndrome, so far no report evaluated the in vivo effects of these compounds on redox homeostasis in cerebellum.