Additionally, the relative metabolite intensities of various amino acids, such as 1-pyrroline-2-carboxylic acid, aminoadipic acid, N-acetylhistamine, l -2,3-dihydrodipicolinate, cysteic acid, and pyrrolidonecarboxylic acid, were up- or downregulated in the model group, indicating that the metabolism of amino acids was altered during ischemia and hypoxia.