Editing Arginine (section)

===Schizophrenia===
Both liquid chromatography and liquid chromatography/mass spectrometric assays have found that brain tissue of deceased people with [[schizophrenia]] shows altered arginine metabolism. Assays also confirmed significantly reduced levels of γ-aminobutyric acid (GABA), but increased [[agmatine]] concentration and glutamate/GABA ratio in the schizophrenia cases. Regression analysis indicated positive correlations between arginase activity and the age of disease onset and between L-ornithine level and the duration of illness. Moreover, cluster analyses revealed that L-arginine and its main metabolites L-citrulline, L-ornithine and agmatine formed distinct groups, which were altered in the schizophrenia group. Despite this, the biological basis of schizophrenia is still poorly understood, a number of factors, such as dopamine hyperfunction, glutamatergic hypofunction, GABAergic deficits, cholinergic system dysfunction, stress vulnerability and neurodevelopmental disruption, have been linked to the aetiology and/or pathophysiology of the disease.<ref>{{cite journal | vauthors = Liu P, Jing Y, Collie ND, Dean B, Bilkey DK, Zhang H |display-authors=3| title = Altered brain arginine metabolism in schizophrenia | journal = Translational Psychiatry | volume = 6 | issue = 8 | pages = e871 | date = August 2016 | pmid = 27529679 | pmc = 5022089 | doi = 10.1038/tp.2016.144 | doi-access = free }}</ref>