Identification of N-carboxyethyl gamma-aminobutyric acid in bovine brain and human cerebrospinal fluid.

The di-carboxylated derivative of spermidine, N-carboxyethyl gamma-aminobutyric acid (CEGABA) has been identified in bovine brain and human cerebrospinal fluid by HPLC. This discovery strongly suggests the existence of a metabolic pathway connecting polyamines and GABA via putreanine and CEGABA through progressive oxidative deamination of the amino terminal groups in spermidine.