Free and peptide-bound amino acids as indicators of ischemic damage of the rabbit spinal cord.

The concentrations of free and peptide-bound amino acids aspartate (Asp), glutamate (Glu), glycine (Gly) and gamma-aminobutyric acid (GABA) were studied following ischemia and recirculation in the ventral and dorsal gray matter of the rabbit spinal cord. No changes in the concentration of amino acids following ten minutes (min) of ischemia and four days of recovery were found. The most significant change after 20 min, and especially 40 min, of ischemia was a decrease in free Asp and GABA levels in both parts of the gray matter. The relatively greater decrease in the concentration of free amino acids in the ventral horns corresponds with the greater morphological damage to this part of spinal cord following ischemia. Following 40 min of ischemia and recirculation decrease in peptide-bound Glu in the ventral horns and Asp and Glu in the dorsal horns was found.