Cytochrome P450 reductase-mediated anaerobic biotransformation of ethanol to 1-hydroxyethyl-free radicals and acetaldehyde

Authors
Diaz Gomez, Maria Isabel; Castro, Gerardo Daniel; Delgado de Layo, A. M. A.; Costantini, Martin Hernan; Castro, Jose Alberto
Publication Year
2000
Language
English
Format
article
Status
Published version
Description
The ability of cytochrome P450 reductase to metabolize ethanol (EtOH) to acetaldehyde (AC) and 1-hydroxyethyl free radicals (1HEt) in anaerobic media was studied. Determination of AC was made by GC-FID analysis of the head space of incubation mixtures. The formation of 1HEt was established by GC-MS analysis of the adduct formed between the radical and the spin trap PBN. Results showed that pure human P450 reductase is able to biotransform EtOH to AC and 1HEt in a NADPH-dependent process under an oxygen-free nitrogen atmosphere. Pure FAD in the presence of NADPH was also able to generate AC and 1HEt from the alcohol. Anaerobic incubation mixtures containing either rat liver microsomes or pure nuclei were also able to biotransform EtOH to AC and 1HEt in the presence of NADPH. These processes were inhibited by antibody against rat liver microsomal P450 reductase. Results suggest that semiquinone forms of the flavin in P450 reductase may biotransform EtOH. These reactions might be of some significance in tissues where the P450 reductase is present in the absence of specific forms of cytochrome P450 known to be involved in EtOH metabolism (e.g. CYP2E1). However the toxicological significance of this enzymatic process remains to be established.
Fil: Diaz Gomez, Maria Isabel. Consejo Nacional de Investigaciones Científicas y Técnicas. GP. CITEFA - Centro de Investigaciones Toxicológicas (I); Argentina
Fil: Castro, Gerardo Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina
Fil: Delgado de Layo, A. M. A.. Consejo Nacional de Investigaciones Científicas y Técnicas. GP. CITEFA - Centro de Investigaciones Toxicológicas (I); Argentina
Fil: Costantini, Martin Hernan. Consejo Nacional de Investigaciones Científicas y Técnicas. GP. CITEFA - Centro de Investigaciones Toxicológicas (I); Argentina
Fil: Castro, Jose Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina
Subject
1-HYDROXYETHYL FREE RADICAL
ACETALDEHYDE
ANAEROBIC BIOTRANSFORMATION
CYTOCHROME P450 REDUCTASE
ETHANOL
Otras Ciencias Biológicas
Ciencias Biológicas
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/71677