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PredicateObject
rdf:type
lifeskim:mentions
pubmed:dateCreated
2003-2-26
pubmed:abstractText
The 2-oxoaldehyde methylglyoxal (MeG) is the precursor to a number of the known advanced glycation endproducts (AGE) implicated in the development of diabetic complications. Other 2-oxoaldehydes that are important in AGE formation, such as glyoxal, glucosone, deoxyglucosone, xylosone and deoxyxylosone, are produced by nonenzymatic reactions. By contrast, MeG is produced by both enzymatic and nonenzymatic processes, most of which appear to be enhanced in diabetes. MeG may be a major precursor to formation of AGE, and rates of production of MeG depend upon physiological conditions such as hyperglycemia and ketoacidosis. MeG is also unique compared to the other 2-oxoaldehydes in its complex metabolism. At least four pathways contribute to detoxification of MeG: (1) aldose reductase, a member of the aldo-keto reductase superfamily, catalyzes the NADPH-dependent reduction of a wide range of aldehydes. MeG is the best of the known physiological aldehyde substrates of aldose reductase. The distribution of aldose reductase in human tissue is restricted; there is little expression in liver; (2) the ubiquitous and highly active glyoxalase system converts MeG into D-lactate. However, this system depends upon the availability of glutathione; activity is severely limited by conditions of oxidative stress that impact levels of glutathione; (3) betaine aldehyde dehydrogenase, also known as ALDH9, is able to catalyze the oxidation of MeG to pyruvate, although less efficiently than with its substrate betaine aldehyde; (4) the long-known but not widely studied 2-oxoaldehyde dehydrogenases (2-ODHs) catalyze the oxidation of MeG to pyruvate, primarily in liver. There are two NADP-dependent 2-ODHs in human liver. Both of these require an activating amine. The physiological activator is unknown.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0009-2797
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
143-144
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
341-51
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2003
pubmed:articleTitle
Methylglyoxal metabolism and diabetic complications: roles of aldose reductase, glyoxalase-I, betaine aldehyde dehydrogenase and 2-oxoaldehyde dehydrogenase.
pubmed:affiliation
Department of Biochemistry and Molecular Biology, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA. dlvanderjagt@salud.unm.edu
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't