imidazoleacetaldehyde and gamma-aminobutyraldehyde , metabolites of histamine and putrescine , respectively , have been shown to be substrates of human liver aldehyde dehydrogenase ( ec 1.2.1.3 ) cytoplasmic ( e1 ) and mitochondrial ( e2 ) isozymes .
C0010834
cytoplasmic
C0026237
mitochondrial