Hepatic aldehyde dehydrogenases and lipid peroxidation

• Published in: Pharmacology, biochemistry and behavior Vol. 18; pp. 155 - 160
• Main Authors: Hjelle, Jerry J., Petersen, Dennis R.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 1983
• Subjects: Aldehyde Dehydrogenase; Aldehyde Oxidoreductases - metabolism; Aldehydes - metabolism; Animals; Cytosol - enzymology; Isoenzymes - metabolism; Isozymes; Kinetics; Lipid peroxidation; Lipid Peroxides - metabolism; Liver; Liver - enzymology; Male; Malonates - metabolism; Malondialdehyde - metabolism; Microsomes, Liver - enzymology; Mitochondria, Liver - enzymology; Rats; Rats, Inbred Strains; Lipid peroxidation; Isozymes; Malondialdehyde metabolism; Aldehyde dehydrogenase; Liver
• ISSN: 0091-3057; 1873-5177
• DOI: 10.1016/0091-3057(83)90164-8

Recent findings have shown that microsomal membrane lipid peroxidation generates a variety of reactive aldehydic products. The interaction of lipid peroxidation products with hepatic aldehyde dehydrogenases (ALDH) was studied using rat liver subcellular fractions. The well-documented membrane peroxidation product malondialdehyde (MDA) was studied to determine if ALDH isozymes play a role in metabolism of this aldehyde. The cytosolic and mitochondrial hepatic subcellular fractions were found to contain ALDH isozymes capable of oxidizing MDA. The kinetic properties of a cytosolic ALDH (K m of approximately 16 μM) suggest that this enzyme may be involved in the metabolism of MDA in vivo. Both the cytosolic and mitochondrial fractions also contained an ALDH isozyme with K m values in the millimolar range. Addition of the cytosolic fraction of rat liver produced a significant decrease in the accumulation of MDA during CCl 4-induced microsomal membrane lipid peroxidation but did not protect cytochrome P-450 from destruction. The mitochandrial low K m ALDH isozyme was found to be a target enzyme for inhibition during in vitro microsomal lipid peroxidation. These studies show that a select ALDH isozyme is sensitive to inhibition during membrane lipid peroxidation whereas other isozymes may be involved in the metabolism of aldehydic peroxidation products.