Editing Arginine (section)

==Research==
===Growth hormone===
Intravenously administered arginine is used in growth hormone stimulation tests<ref>{{MedlinePlusEncyclopedia|003377|Growth hormone stimulation test}}</ref> because it stimulates the secretion of [[growth hormone]].<ref>{{cite journal | vauthors = Alba-Roth J, Müller OA, Schopohl J, von Werder K | s2cid = 7488757 | title = Arginine stimulates growth hormone secretion by suppressing endogenous somatostatin secretion | journal = The Journal of Clinical Endocrinology and Metabolism | volume = 67 | issue = 6 | pages = 1186–9 | date = December 1988 | pmid = 2903866 | doi = 10.1210/jcem-67-6-1186 }}</ref> A review of clinical trials concluded that oral arginine increases growth hormone, but decreases growth hormone secretion, which is normally associated with exercising.<ref>{{cite journal | vauthors = Kanaley JA | title = Growth hormone, arginine and exercise | journal = Current Opinion in Clinical Nutrition and Metabolic Care | volume = 11 | issue = 1 | pages = 50–4 | date = January 2008 | pmid = 18090659 | doi = 10.1097/MCO.0b013e3282f2b0ad | s2cid = 22842434 }}</ref> However, a more recent trial reported that although oral arginine increased plasma levels of <small>L</small>-arginine it did not cause an increase in growth hormone.<ref>{{cite journal | vauthors = Forbes SC, Bell GJ | title = The acute effects of a low and high dose of oral L-arginine supplementation in young active males at rest | journal = Applied Physiology, Nutrition, and Metabolism| volume = 36 | issue = 3 | pages = 405–11 | date = June 2011 | pmid = 21574873 | doi = 10.1139/h11-035 }}</ref>

===Herpes-Simplex Virus (Cold sores)===
Research from 1964 into amino acid requirements of [[herpes simplex virus]] in human cells indicated that "...the lack of arginine or [[histidine]], and possibly the presence of [[lysine]], would interfere markedly with virus synthesis", but concludes that "no ready explanation is available for any of these observations".<ref>{{cite journal | vauthors = Tankersley RW |title=Amino Acid Requirements of Herpes Simplex Virus in Human Cells |journal=Journal of Bacteriology |date=March 1964 |volume=87 |issue=3 |pages=609–613 |doi=10.1128/jb.87.3.609-613.1964 |pmid=14127578 |pmc=277062 |doi-access=free }}</ref>

Further reviews conclude that "lysine's efficacy for [[herpes labialis]] may lie more in prevention than treatment." and that "the use of lysine for decreasing the severity or duration of outbreaks" is not supported, while further research is needed.<ref>{{cite journal | vauthors = Tomblin FA, Lucas KH | title = Lysine for management of herpes labialis | journal = American Journal of Health-System Pharmacy | volume = 58 | issue = 4 | pages = 298–300, 304 | date = February 2001 | pmid = 11225166 | doi = 10.1093/ajhp/58.4.298 | doi-access = free }}</ref> A 2017 study concludes that "clinicians could consider advising patients that there is a theoretical role of lysine supplementation in the prevention of herpes simplex sores but the research evidence is insufficient to back this. Patients with cardiovascular or gallbladder disease should be cautioned and warned of the theoretical risks."<ref>{{cite journal | vauthors = Mailoo VJ, Rampes S | title = Lysine for Herpes Simplex Prophylaxis: A Review of the Evidence | journal = Integrative Medicine | volume = 16 | issue = 3 | pages = 42–46 | date = June 2017 | pmid = 30881246 | pmc = 6419779 }}</ref>

===High blood pressure===
A meta-analysis showed that <small>L</small>-arginine reduces blood pressure with pooled estimates of 5.4 mmHg for systolic blood pressure and 2.7 mmHg for diastolic blood pressure.<ref>{{cite journal | vauthors = Dong JY, Qin LQ, Zhang Z, Zhao Y, Wang J, Arigoni F, Zhang W |display-authors=3| title = Effect of oral L-arginine supplementation on blood pressure: a meta-analysis of randomized, double-blind, placebo-controlled trials | journal = American Heart Journal | volume = 162 | issue = 6 | pages = 959–65 | date = December 2011 | pmid = 22137067 | doi = 10.1016/j.ahj.2011.09.012 | department = review }}</ref>

Supplementation with {{sm|l}}-arginine reduces [[diastolic blood pressure]] and lengthens pregnancy for women with [[gestational hypertension]], including women with high blood pressure as part of [[pre-eclampsia]]. It did not lower systolic blood pressure or improve [[Birth weight|weight at birth]].<ref>{{cite journal | vauthors = Gui S, Jia J, Niu X, Bai Y, Zou H, Deng J, Zhou R |display-authors=3| title = Arginine supplementation for improving maternal and neonatal outcomes in hypertensive disorder of pregnancy: a systematic review | journal = Journal of the Renin-Angiotensin-Aldosterone System | volume = 15 | issue = 1 | pages = 88–96 | date = March 2014 | pmid = 23435582 | doi = 10.1177/1470320313475910 | department = (review) | doi-access = free }}</ref>

===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>

===Raynaud's phenomenon===
Oral L-arginine has been shown to reverse digital necrosis in [[Raynaud syndrome]].<ref>{{Cite journal |last1=Rembold |first1=Christopher M. |last2=Ayers |first2=Carlos R. |date=February 2003 |title=Oral L-arginine can reverse digital necrosis in Raynaud's phenomenon |url=https://pubmed.ncbi.nlm.nih.gov/12701823/ |journal=Molecular and Cellular Biochemistry |volume=244 |issue=1–2 |pages=139–141 |doi=10.1023/A:1022422932108 |issn=0300-8177 |pmid=12701823|s2cid=30249281 }}</ref>