Participation of aldehyde dehydrogenase in the oxidative deamination pathway of histamine and putrescine.

Some guinea pig tissue homogenates have shown the ability to catabolize, in vitro, imidazoloacetaldehyde (ImAAL) and gamma-aminobutyraldehyde (GABAL) via NAD-dependent aldehyde dehydrogenase (ALDH, EC 1.2.1.3). The liver, kidney, small intestine and gastric mucosa are the richest sources of ALDH activity towards ImAAL. The liver, kidney, small intestine and pancreas also show ALDH activity with GABAL as a substrate. All tissues tested have shown low Km and high Km ALDH activity with propionaldehyde as substrate. The guinea pig liver ALDH which is able to oxidize ImAAL and GABAL is located exclusively in the cytoplasm.