YOUNGSTERS CANNOT HANDLE D-AMINO ACIDS

"Younger animals have lower amounts of D amino acid oxidases and consequently higher concentrations of free D-amino acids compared to adult animals. If the ingested D-amino acids are not metabolized by these enzymes, they will accumulate in the tissues and may provoke serious damage leading to suppression of the synthesis of other essential enzymes and inhibition of the growth rate of the animals", an Italian research team says.

Amino acids can be exist in L or D forms of photo isomers - that means non superimposable  mirror images of same molecule. Usually, L amino acids naturally exist in animal bodies in abundance. D isomers often comes from synthetic sources. When an animal ingests a D amino acid, it absorbs from intestine and is transported through blood stream to organs such as liver and kidneys. These organs either have or produce D amino acid oxidases, to detoxify D amino acids.



Under mentioned process of D amino acid oxidase or Aspartate oxidase produces ammonia and hydrogen peroxide as toxic byproducts. They increase oxidative stress, hence the need for antioxidants are raised.

If mother ingests these free D-amino acids in her pregnancy, young rats showed increased production of D-amino acid oxidases. "Specifically, when a mother rat ingests D-Ala or D-Asp during pregnancy and suckling, an increase in D-amino acid oxidase or D-aspartate oxidase is observed in the liver and kidneys of the baby rats", Dr. Aniello, the lead scientist of current study explains.

Source:

Biological role of D-amino acid oxidase and D-aspartate oxidase. Effects of D-amino acids.

A D'Aniello, G D'Onofrio, M Pischetola, G D'Aniello, A Vetere, L Petrucelli, G H Fisher

December 25, 1993The Journal of Biological Chemistry268, 26941-26949.