Changes in concentrations of methylglyoxal, D-lactate and glyoxalase activities in liver and plasma of rats fed a 3'-methyl-4-dimethylaminoazobenzene-rich diet.
Donryu male albino rats were fed a diet containing 0.064% 3'-methyl-4-dimethylaminoazobenzene (MDAB) for 21 weeks. During the ensuing rat liver carcinogenesis, changes in the concentrations of methylglyoxal, D-lactate and glutathione as well as activities of glyoxalase I and II in liver and plasma were examined. After the start of the diet, hepatic contents of methylglyoxal and D-lactate increased to about 7 and 3 times that of the control, respectively. However, after 21 weeks the D-lactate content decreased from the elevated level, but remained at a higher level of 1.4 times the control. The hepatic glyoxalase I activity increased 1.2 to 1.7 times over the control during carcinogenesis, while glyoxalase II activity increased 160% during the precancerous state and decreased to 55% of control at 21 weeks. the hepatic level of reduced glutathione (GSH) increased and peaked after 4 weeks of the MDAB diet and decreased thereafter to 57% of the control level after 21 weeks. Both pyruvate and L-lactate levels increased in the liver and plasma of MDAB-fed rats when rats had obvious symptoms of hepatoma.
Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, Okayama University, Japan.
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Kawase
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Tada
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Akagi
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Ohmori
D000410:Alanine Transaminase / Q000097:blood / Q000378:metabolism; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D002273:Carcinogens / Q000494:pharmacology / Q000633:toxicity; D004032:Diet; D005978:Glutathione / Q000032:analysis / Q000378:metabolism; D007773:Lactates / Q000097:blood / Q000378:metabolism*; D007791:Lactoylglutathione Lyase / Q000097:blood / Q000378:metabolism*; D008113:Liver Neoplasms / Q000737:chemistry / Q000378:metabolism*; D008297:Male; D008749:Methyldimethylaminoazobenzene / Q000494:pharmacology* / Q000633:toxicity; D009929:Organ Size / Q000187:drug effects; D011765:Pyruvaldehyde / Q000097:blood / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D013869:Thiolester Hydrolases / Q000097:blood / Q000378:metabolism*; D005723:gamma-Glutamyltransferase / Q000097:blood / Q000378:metabolism; D000099301:Hydroxyacylglutathione Hydrolase
D000410:Alanine Transaminase; D001219:Aspartate Aminotransferases; D002273:Carcinogens; D005978:Glutathione; D007773:Lactates; D007791:Lactoylglutathione Lyase; D008749:Methyldimethylaminoazobenzene; D011765:Pyruvaldehyde; D013869:Thiolester Hydrolases; D005723:gamma-Glutamyltransferase; D000099301:Hydroxyacylglutathione Hydrolase