Elevated plasma nitrate levels in depressive states.
BACKGROUND
Previous studies have shown that nitric oxide (NO) synthase inhibitors show preclinical antidepressant-like properties, suggesting that NO is involved in the pathogenesis of depression. The purpose of this study is to examine whether or not NO production increases in depressed patients.


METHODS
Plasma nitrate concentrations, an index of NO production, were measured by high-performance liquid chromatography in depressed patients (n=17) and compared with patients suffering anxiety (n=6) and with healthy controls (n=12).


RESULTS
Plasma nitrate concentrations were significantly higher in depressed patients than in patients with an anxiety disorder (P<0.05) or in controls (P<0.01).


CONCLUSIONS
The study group was small. The source of the surplus production of NO in patients with major depressive episode remains unclear.


CONCLUSIONS
These results suggest that NO production is increased in depression.
Department of Neuropsychiatry, Keio University School of Medicine, 35 Shinanomachi, Shinjuku Ward, Tokyo 160-8582, Japan. e-suzuki@med.keio.ac.jp
E
E
Suzuki
G
G
Yagi
T
T
Nakaki
S
S
Kanba
M
M
Asai
D000328:Adult; D001008:Anxiety Disorders / Q000503:physiopathology*; D015415:Biomarkers / Q000032:analysis; D003863:Depression / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D009566:Nitrates / Q000097:blood* / Q000378:metabolism; D009569:Nitric Oxide / Q000096:biosynthesis* / Q000097:blood
D015415:Biomarkers; D009566:Nitrates; D009569:Nitric Oxide