Cumene peroxide and Fe(2+)-ascorbate-induced lipid peroxidation and effect of phosphoglucose isomerase.
Malondialdehyde (MDA) is one of cytotoxic aldehydes produced in cells as a result of lipid peroxidation and further MDA metabolism in cytoplasm is not known. In our experiments the liver fraction 10,000 g containing phosphoglucose isomerase and enzymes of the glyoxalase system was used and obtained experimental data shows that in this fraction there is an aggregate of reactions taking place both in membranes (lipid peroxidation) and outside membranes. MDA accumulation is relatively slow because MDA is a substrate of aldehyde isomerase (MDA <--> methylglyoxal). The well known enzyme phosphoglucose isomerase acts as an aldehyde isomerase (Michaelis constant for this enzyme Km = 133 +/- 8 microM). MDA conversion to methylglyoxal and further to neutral product D-lactate (with GSH as a cofactor) occurs in cytoplasm and D-lactate should be regarded as the end product of two different parametabolic reactions: lipid peroxidation or protein glycation.
Research Center of Cardiology, Ministry of Public Health of Russian Federation, Moscow, Russia. zira-aga@yandex.ru
Z S
ZS
Agadjanyan
S F
SF
Dugin
L F
LF
Dmitriev
D000818:Animals; D001205:Ascorbic Acid / Q000494:pharmacology*; D001555:Benzene Derivatives / Q000494:pharmacology*; D005296:Ferrous Compounds / Q000494:pharmacology*; D005956:Glucose-6-Phosphate Isomerase / Q000378:metabolism*; D007700:Kinetics; D019344:Lactic Acid / Q000378:metabolism; D015227:Lipid Peroxidation / Q000187:drug effects*; D008099:Liver / Q000378:metabolism; D008315:Malondialdehyde / Q000737:chemistry / Q000378:metabolism; D010545:Peroxides / Q000494:pharmacology*; D051381:Rats; D017208:Rats, Wistar
D001555:Benzene Derivatives; D005296:Ferrous Compounds; D010545:Peroxides; C051140:iron(II)-ascorbic acid complex; D019344:Lactic Acid; D008315:Malondialdehyde; C015763:cumene; D005956:Glucose-6-Phosphate Isomerase; D001205:Ascorbic Acid