Intracerebral accumulation of glutaric and 3-hydroxyglutaric acids secondary to limited flux across the blood-brain barrier constitute a biochemical risk factor for neurodegeneration in glutaryl-CoA dehydrogenase deficiency

J Neurochem. 2006 May;97(3):899-910. doi: 10.1111/j.1471-4159.2006.03813.x. Epub 2006 Mar 29.


Glutaric acid (GA) and 3-hydroxyglutaric acids (3-OH-GA) are key metabolites in glutaryl co-enzyme A dehydrogenase (GCDH) deficiency and are both considered to be potential neurotoxins. As cerebral concentrations of GA and 3-OH-GA have not yet been studied systematically, we investigated the tissue-specific distribution of these organic acids and glutarylcarnitine in brain, liver, skeletal and heart muscle of Gcdh-deficient mice as well as in hepatic Gcdh-/- mice and in C57Bl/6 mice following intraperitoneal loading. Furthermore, we determined the flux of GA and 3-OH-GA across the blood-brain barrier (BBB) using porcine brain microvessel endothelial cells. Concentrations of GA, 3-OH-GA and glutarylcarnitine were significantly elevated in all tissues of Gcdh-/- mice. Strikingly, cerebral concentrations of GA and 3-OH-GA were unexpectedly high, reaching similar concentrations as those found in liver. In contrast, cerebral concentrations of these organic acids remained low in hepatic Gcdh-/- mice and after intraperitoneal injection of GA and 3-OH-GA. These results suggest limited flux of GA and 3-OH-GA across the BBB, which was supported in cultured porcine brain capillary endothelial cells. In conclusion, we propose that an intracerebral de novo synthesis and subsequent trapping of GA and 3-OH-GA should be considered as a biochemical risk factor for neurodegeneration in GCDH deficiency.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acids / metabolism
  • Animals
  • Biological Transport / physiology
  • Blood-Brain Barrier / physiopathology*
  • Blotting, Western / methods
  • Brain / cytology
  • Brain / metabolism*
  • Carnitine / analogs & derivatives
  • Carnitine / metabolism
  • Cells, Cultured
  • Dicarboxylic Acids / metabolism
  • Disease Models, Animal
  • Endothelial Cells / metabolism
  • Glucose / metabolism
  • Glutarates / metabolism*
  • Glutaryl-CoA Dehydrogenase / deficiency*
  • Heart / physiology
  • Liver / metabolism
  • Mice
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Models, Biological
  • Muscles / metabolism
  • Neurodegenerative Diseases / genetics
  • Neurodegenerative Diseases / physiopathology*
  • Risk Factors
  • Statistics, Nonparametric
  • Swine
  • Time Factors
  • Tissue Distribution / physiology


  • 3-hydroxyglutaric acid
  • Amino Acids
  • Dicarboxylic Acids
  • Glutarates
  • acylcarnitine
  • Glutaryl-CoA Dehydrogenase
  • glutaric acid
  • Glucose
  • Carnitine