Fluorometrical analysis of guanidino compounds in human cerebrospinal fluid

Guanidino compounds in CSF of 57 human subjects were determined fluorometrically after reaction with phenanthrenequinone in alkali solution, using HPLC. Creatinine (65.2 +/- 13.4 nmol/ml), arginine (24.7 +/- 6.4 nmol/ml), and homoarginine (0.7 +/- 0.3 nmol/ml) were found in all subjects. Trace amounts of guanidinosuccinic acid and guanidinoacetic acid were detected in some of the subjects. Brain guanidino compounds, taurocyamine, N-acetylarginine, and methylguanidine were not detected in CSF.