[Quantitative fluorometric determination of 4-aminobutyric acid in cerebrospinal fluid using an amino acid analyzer].
A rapid and simple procedure is described for the determination of 4-aminobutyric acid in human CSF. The o-phthaldialdehyde derivative of 4-aminobutyric acid is analysed with a slightly modified commercially available Amino Acid Analyser. We investigated the sample preparation with special emphasis on the sulphosalicylic acid-induced hydrolysis of 4-aminobutyric acid containing compounds in human liquor. Our experiments demonstrate that the amount of estimated 4-aminobutyric acid depends considerably on the sulphosalicylic acid concentration used for protein precipitation. Application of ultrafiltration instead of sulphosalicylic acid precipitation resulted in markedly decreased 4-aminobutyric acid values. By first using ultrafiltration and by minimizing the time between lumbar puncture and analysis, it was shown that protein precipitation with a concentration of sulphosalicylic acid as low as 5 g/l gives 4-aminobutyric acid values in CSF that are essentially correct.
D000596:Amino Acids / Q000032:analysis; D001322:Autoanalysis / Q000295:instrumentation; D001557:Benzenesulfonates; D006801:Humans; D012459:Salicylates / Q000134:cerebrospinal fluid; D013050:Spectrometry, Fluorescence / Q000295:instrumentation; D014462:Ultrafiltration; D005680:gamma-Aminobutyric Acid / Q000134:cerebrospinal fluid*
D000596:Amino Acids; D001557:Benzenesulfonates; D012459:Salicylates; D005680:gamma-Aminobutyric Acid; C003366:sulfosalicylic acid
Quantitative fluorimetrische Bestimmung der 4-Aminobuttersäure aus Liquor mit einem Aminosäurenanalysator.