Biogenic Aldehydes in Brain: On Their Preparation and Reactions with Rat Brain Tissue

Abstract

When 1 mM serotonin, dopamine, or norepinephrine was incubated with a monoamine oxidase preparation (mitochondrial membranes) in the presence of 4 mM sodium bisulfite, 85-95% of the amines were oxidized to the corresponding aldehydes. In the absence of bisulfite, the recoveries were only approximately 30%, and dark colored products were formed during the incubations. The aldehydes derived from tyramine, octopamine, methoxytyramine, and normetanephrine were also prepared by the use of this method. The bisulfite-aldehyde compounds were stable during storage at -20 degrees C. Bisulfite-free aldehyde solutions were made by diethylether extraction. When the aldehydes derived from dopamine or serotonin were incubated with rat brain homogenates, they were found to disappear in an aldehyde dehydrogenase- and aldehyde reductase-independent manner. The disappearance of the latter aldehyde was more pronounced, and the results indicated that this aldehyde may react with both proteins and phospholipids.

Aldehyde dehydrogenase activity in xenografted human brain tumor in nude mice. Preliminary results in human glioma biopsies

“…These data further earlier reports suggesting a relationship between the ALDH activity and the carcinostatic effects of aliphatic aldehydes [13]. In brain, ALDH plays an important role in the oxidation of aldehydes originating from biogenic amines [1,14]. Among these biogenic amines, high polyamine concentrations are found in brain tumor tissues [15] and a correlation between the glioma histological grade and the activity of enzymes involved in the polyamine pathway has been demonstrated [16].…”

Inactivation of glyceraldehyde-3-phosphate dehydrogenase by the dopamine metabolite, 3,4-dihydroxyphenylacetaldehyde

“…DOPAL was biosynthesized via rat liver MAO procedure as previously established [15]. Stock concentrations were determined using an ALDH assay with nicotinamide adenine dinucleotide (NAD + ) and HPLC [16].…”

“…Metabolism of DOPAL is by aldehyde dehydrogenase (ALDH2) to 3,4-dihydroxyphenylacetic acid (DOPAC) and by cytosolic aldehyde reductase (AR) to 3,4-dihydroxyphenyletanol (DOPET) [10]. Due to its high electrophilicity, DOPAL modifies proteins [12–14] and is toxic to neurons [12, 15–17]. In fact, DOPAL is several of magnitudes more toxic than DA in vitro and in vivo [10, 18].…”

Expression and initial characterization of human ALDH3B1

“…Malondialdehyde (MDA) was synthesized as described previously [14]. 3,4-Dihydroxyphenylacetaldehyde (DOPAL) was synthesized as described previously [15], with minor modification. Briefly, DOPAL-bisulfite was produced by incubating dopamine with monoamine oxidase (Sigma) and sodium bisulfite.…”