Positive correlation between contamination by blood and amino acid levels in cerebrospinal fluid of the rat.
The degree of contamination by blood in macroscopically clear cerebrospinal fluid (CSF) from the rat was assessed by the red blood cell count. Amino acid concentrations in the same samples were determined using high performance liquid chromatography. A significant positive correlation between the number of erythrocytes and amino acid concentration was found for alanine, asparagine, aspartate, citrulline, glutamate, glycine, phenylalanine and taurine but not for glutamine, histidine, isoleucine, leucine, lysine, methionine, ornithine, serine, threonine, tyrosine and valine. The difference in amino acid concentration between samples that were or were not contaminated by blood was as much as one order of magnitude for aspartate, glutamate, glycine and taurine; the concentrations of these amino acids were highly correlated with the erythrocyte counts (r = 0.87, P = 0.000002 for glutamate). The results suggest that macroscopical inspection is often not sufficient to judge contamination by blood in the CSF.
D000596:Amino Acids / Q000134:cerebrospinal fluid*; D000818:Animals; D001772:Blood Cell Count; D001774:Blood Chemical Analysis; D002555:Cerebrospinal Fluid / Q000032:analysis* / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains
D000596:Amino Acids