During inflammation, arginine amino acid residues can be enzymatically converted into citrulline residues in proteins such as vimentin, by a process called citrullination.
22.
It has also been demonstrated " in vitro " that arginine down-regulates argininosuccinate synthetase expression, while citrulline up-regulates it.
23.
L-Canaline is a substrate for ornithine aminotransferase resulting in the synthesis of L-ureidohomoserine ( the corresponding analog of L-citrulline ).
24.
However, recycling is not quantitative because citrulline accumulates along with nitrate and nitrite, the stable end-products of NO, in NO-producing cells.
25.
In the body, citrulline is produced as a byproduct of the enzymatic production of nitric oxide from the amino acid arginine, catalyzed by nitric oxide synthase.
26.
An individual with untreated OTC deficiency will show decreased citrulline and arginine concentrations ( because the enzyme block is proximal to these intermediates ) and increased orotic acid.
27.
See Process for the production of L-citrulline from watermelon flesh and rind : http : / / www . google . com / patents / US8173837.
28.
Based on this reaction, Krebs and Henseleit postulated that in living cells, similar reaction could occur, and that ornithine and citrulline could be the intermediate reactions.
29.
As a result, nitrogen ( in the form of ammonia ) and other byproducts of the urea cycle ( such as citrulline ) build up in the bloodstream.
30.
Arginine is then synthesized from citrulline in the urea cycle by the sequential action of the cytosolic enzymes argininosuccinate synthetase ( ASS ) and argininosuccinate lyase ( ASL ).
