Heterogeneity of NADPH-Dependent Aldehyde Reductase from Human and Rat Brain.

Four multiple molecular forms of NADPH- dependent aldehyde reductase are isolated by ion-exchange and gel chromatography from human brains. Using the same procedure two multiple forms of NADPH- dependent aldehyde reductase are found in rat brain. The molecular weight of two of the forms of human brain aldehyde reductase is 4000 and of the other two it is 4000. Large differences with respect to substrate specificity with a wide range of aliphatic and aromatic aldehydes are obderved between the multiple enxyme forms of each species. All enzyme forms use NADPH ae coenzyme; additionally one enzyme of each species can use NADPH as well. Classical inhibitors of aldehyde and alcohol dehydrogenase do not affect the activity of the multiple molecular forms of aldehyde reductase from human and rat brain, but psychoactive substances such as barbiturates and chlorpronizine as well "biogenic" acids are inhibitory. [ABSTRACT FROM AUTHOR]