Carnitine and the elimination of potentially toxic metabolites

http://www.carnitinaofficialsite.it/cms/index.php?option=com_content&view...

Carnitine is essential for the transport of acyl groups out of the mitochondria and from the peroxisomes.

In some diseases characterised by alterations of fatty acid or branched-chain amino acid metabolism (e.g. organic acidemias), short or medium chain acyl- CoA groups can accumulate inside mitochondria or peroxisomes. Carnitine allows these intermediates of oxidation processes to be transported out of intracellular organelles in the form of acylcarnitine. This transport is catalysed by the carnitine acyltransferase ( CAT) and carnitine-acylcarnitine translocase ( CT) enzymes. Carnitine thus prevents the accumulation of acyl groups which, if present in excess, can destabilise the mitochondrial membrane. In this process, carnitine increases within the mitochondria the availability of free CoA (that is, not linked to acyl groups), which is an essential intermediate in many metabolic reactions.

Toxic metabolites can form also following treatment with some drugs (for example valproic acid, or pivalic acid-conjugated antibiotics). These drugs are metabolised by acyl-CoA and if they are not eliminated by the action of carnitine, they can accumulate and have a cytotoxic effect.

There is a long list of enzymes which are inhibited by high concentrations of acyl-CoA, such as for example acetyl-CoA carboxylase, adenine nucleotide translocase and pyruvate dehydrogenase. Serious metabolic changes with complex clinical pictures result.

For this reason, the job carried out by carnitine in removing the accumulation of these metabolites is extremely important. In these conditions (metabolic diseases, treatment with certain drugs), an increased demand by the body for carnitine, associated with increased elimination of acylcarnitine, results in excessive use of the available carnitine, which can lead to a secondary carnitine deficiency.

Category:

Science & Technology

Tags:

• Carnitine
• energy
• metabolism
• amino
• acids
• mitochondria
• mitochondrion
• fat
• burn
• acilcarnitinas
• acetilcarnitina
• ácidos
• grasos
• proteínas
• propionilcarnitina
• beta
• oxidación
• metabolismo
• glucosa

[emerson24]

Nothing worse than someone with a heavy foreign accent explaining the intricacies of biochemistry.