Arginine, citrulline and nitrate concentrations in the cerebrospinal fluid from patients with acute hydrocephalus.
Citrulline and nitric oxide (NO) are synthesized by NO synthase (NOS) in a 1:1-stoichiometry. In this study, we determined by HPLC arginine and citrulline concentrations by fluorescence detection and nitrate levels by UV absorbance detection in the cerebrospinal fluid (CSF) from patients with acute hydrocephalus that underwent ventricular drainage. We found increased citrulline concentration (50.6+/-17.2 versus 20.9+/-2.0 microM) and decreased arginine/citrulline molar ratio (0.42+/-0.11 versus 1.12+/-0.16) in hydrocephalus patients, while arginine and nitrate concentrations and citrulline/nitrate molar ratio remained with little change. Citrulline has been determined as a marker of NOS activity in some studies, but it remains to be determined the extent at which this statement holds true, since other biochemical pathways also regulate the concentration of this amino acid. Our results suggest that citrulline is primarily synthesized from NOS in acute hydrocephalus. The evaluation of sample deproteinization by addition of methanol for the analysis of amino acids in CSF is also reported.
Pérez-Neri
Iván
I
Department of Neurochemistry, National Institute of Neurology and Neurosurgery, Insurgentes Sur 3877, La Fama, Tlalpan, 14269, Mexico City, Mexico.
Castro
Elvira
E
Montes
Sergio
S
Boll
Marie-Catherine
MC
Barges-Coll
Juan
J
Soto-Hernández
José Luis
JL
Ríos
Camilo
C
D000328:Adult; D000418:Albumins / Q000302:isolation & purification; D000596:Amino Acids / Q000134:cerebrospinal fluid; D001120:Arginine / Q000134:cerebrospinal fluid*; D016022:Case-Control Studies; D002956:Citrulline / Q000134:cerebrospinal fluid*; D006801:Humans; D006849:Hydrocephalus / Q000134:cerebrospinal fluid*; D008875:Middle Aged; D009566:Nitrates / Q000134:cerebrospinal fluid*
D000418:Albumins; D000596:Amino Acids; D009566:Nitrates; D002956:Citrulline; D001120:Arginine