Aldehyde dehydrogenase activity in brain and liver of the rainbow trout (Salmo gairdneri Richardson)

✍ Scribed by Nilsson, Göran E.

• Publisher: John Wiley and Sons
• Year: 1988
• Tongue: English
• Weight: 921 KB
• Volume: 247
• Category: Article
• ISSN: 0022-104X
• DOI: 10.1002/jez.1402470302

✦ Synopsis

Aldehyde dehydrogenase (ALDH) activity was measured in brain and liver of rainbow trout by using 3,4-dihydroxyphenylacetaldehyde (DOPAL, the biogenic aldehyde derived from dopamine) as the substrate. The amount of the corresponding acid produced was quantified by highperformance liquid chromatography with electrochemical detection. Both in brain and liver, the ALDH activity showed a high affinity for the substrate with an apparent K, of 3.7 p M in brain and 2.4 pM in liver. The kinetic experiments with brain ALDH also indicated the presence of an isozyme with a low affinity for DOPAL with a K, around 150 pM. The V, , of the liver ALDH activity varied between 179 and 536 nmoUmin-g, i.e., about 25-75 times higher than that of the low-K, activity in brain. The ALDH activity showed a maximum around pH 8.5, it was stimulated by M?+, and disulfwam was found to be a potent inhibitor of the enzyme. The results suggested that the majority of the ALDH activity was located in mitochondria (60-70% with regard to the brain and 70-80% with regard to the liver), while the remaining activity appeared to be cytosolic in both organs. No microsomal ALDH activity could be found.