Related Experiment Videos
Hepatic aldehyde dehydrogenases and lipid peroxidation
Pharmacology, Biochemistry, and Behavior
|January 1, 1983
Summary
Hepatic aldehyde dehydrogenases (ALDH) metabolize reactive aldehydes from lipid peroxidation. A specific cytosolic ALDH may detoxify malondialdehyde (MDA), while mitochondrial ALDH is inhibited by lipid peroxidation.
Area of Science:
- Biochemistry
- Cell Biology
- Toxicology
Background:
- Microsomal membrane lipid peroxidation generates reactive aldehydic products.
- Hepatic aldehyde dehydrogenases (ALDH) are crucial for aldehyde metabolism.
- Malondialdehyde (MDA) is a well-documented product of lipid peroxidation.
Purpose of the Study:
- To investigate the interaction between lipid peroxidation products and hepatic ALDH isozymes.
- To determine the role of ALDH isozymes in the metabolism of MDA.
- To assess the sensitivity of ALDH isozymes to inhibition during lipid peroxidation.
Main Methods:
- Utilized rat liver subcellular fractions (cytosolic and mitochondrial).
- Studied the kinetic properties of ALDH isozymes involved in MDA oxidation.
- Investigated the effect of cytosolic fraction on MDA accumulation and cytochrome P-450 during CCl4-induced lipid peroxidation.
Main Results:
- Both cytosolic and mitochondrial fractions contain ALDH isozymes capable of oxidizing MDA.
- A cytosolic ALDH with a low Km (approx. 16 microM) suggests in vivo MDA metabolism involvement.
- Mitochondrial low Km ALDH is inhibited during in vitro lipid peroxidation, while cytosolic fraction reduces MDA accumulation but not cytochrome P-450 destruction.
Conclusions:
- Specific ALDH isozymes are involved in metabolizing aldehydic peroxidation products like MDA.
- A select mitochondrial ALDH isozyme is sensitive to inhibition by lipid peroxidation.
- Cytosolic ALDH plays a role in detoxifying MDA, but does not protect against cytochrome P-450 damage.