Simultaneous determination of N-acetylaspartic acid, N-acetylglutamic acid, and N-acetylaspartylglutamic acid in whole brain of 3-mercaptopropionic acid-treated rats using liquid chromatography-atmospheric pressure chemical ionization mass spectrometry

The measurement of N-acetylaspartic acid (NAA), N-acetylglutamic acid (NAG) , and N-acetylaspartyl-glutamic acid (NAAG) in the whole brain of 3-mercapt opropionic acid (3-MPA)-treated rats has been developed using Liquid chroma tography-mass spectrometry with an atmospheric pressure ionization interfac e system. The recoveries of these compounds were 90.85 +/- 3.43% for NAA, 9 1.62 +/- 5.47% for NAG, and 92.29 +/- 4.44% far NAAG. The detection Limits for NAA, NAG, and NAAG were 12, 15, and 20 mu g/ml, respectively. After adm inistration of 3-MPA, the concentrations of NAA NAG, and NAAG in the whole brain over 10 min increased 177.25, 134.23, and 127.70%, respectively. Thes e concentrations then decreased over the next 60 min. The simultaneous dete rmination of NAA, NAG, and NAAG using this method was found to be very usef ul for studies of metabolism of NAA, NAG, and NAAG in biological samples. ( C) 1999 Academic Press.