title: Protective effect of creatine against inhibition by methylglyoxal of mitochondrial respiration of cardiac cells.
abstract: Previous publications from our laboratory have shown that methylglyoxal inhibits mitochondrial respiration of malignant and cardiac cells, but it has no effect on mitochondrial respiration of other normal cells [Biswas, Ray, Misra, Dutta and Ray (1997) Biochem. J. 323, 343-348; Ray, Biswas and Ray (1997) Mol. Cell. Biochem. 171, 95-103]. However, this inhibitory effect of methylglyoxal is not significant in cardiac tissue slices. Moreover, post-mitochondrial supernatant (PMS) of cardiac cells could almost completely protect the mitochondrial respiration against the inhibitory effect of methylglyoxal. A systematic search indicated that creatine present in cardiac cells is responsible for this protective effect. Glutathione has also some protective effect. However, creatine phosphate, creatinine, urea, glutathione disulphide and beta-mercaptoethanol have no protective effect. The inhibitory and protective effects of methylglyoxal and creatine respectively on cardiac mitochondrial respiration were studied with various concentrations of both methylglyoxal and creatine. Interestingly, neither creatine nor glutathione have any protective effect on the inhibition by methylglyoxal on the mitochondrial respiration of Ehrlich ascites carcinoma cells. The creatine and glutathione contents of several PMS, which were tested for the possible protective effect, were measured. The activities of two important enzymes, namely glyoxalase I and creatine kinase, which act upon glutathione plus methylglyoxal and creatine respectively, were also measured in different PMS. Whether mitochondrial creatine kinase had any role in the protective effect of creatine had also been investigated using 1-fluoro-2,4-dinitrobenzene, an inhibitor of creatine kinase. The differential effect of creatine on mitochondria of cardiac and malignant cells has been discussed with reference to the therapeutic potential of methylglyoxal.
authors.affiliation: Department of Biological Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata-700 032, India.
authors.forename: Soumya Sinha
authors.initials: SS
authors.lastname: Roy
authors.forename: Swati
authors.initials: S
authors.lastname: Biswas
authors.forename: Manju
authors.initials: M
authors.lastname: Ray
authors.forename: Subhankar
authors.initials: S
authors.lastname: Ray
mesh_terms: D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism / Q000473:pathology* / Q000517:prevention & control*; D002316:Cardiotonic Agents / Q000494:pharmacology; D019069:Cell Respiration / Q000187:drug effects*; D002645:Chickens; D003401:Creatine / Q000378:metabolism / Q000494:pharmacology*; D003402:Creatine Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D052281:Creatine Kinase, Mitochondrial Form; D003404:Creatinine / Q000494:pharmacology*; D004139:Dinitrofluorobenzene / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D019803:Glutathione Disulfide / Q000378:metabolism / Q000494:pharmacology; D006019:Glycolysis; D006041:Goats; D006321:Heart / Q000187:drug effects; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism*; D007791:Lactoylglutathione Lyase / Q000378:metabolism*; D008623:Mercaptoethanol / Q000494:pharmacology; D051379:Mice; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000378:metabolism; D008931:Mitochondria, Muscle / Q000187:drug effects / Q000378:metabolism; D010101:Oxygen Consumption / Q000187:drug effects*; D010725:Phosphocreatine / Q000494:pharmacology; D011765:Pyruvaldehyde / Q000378:metabolism / Q000494:pharmacology*; D051381:Rats; D014407:Tumor Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D014508:Urea / Q000494:pharmacology
chemical_list: D002316:Cardiotonic Agents; D007527:Isoenzymes; D010725:Phosphocreatine; D008623:Mercaptoethanol; D011765:Pyruvaldehyde; D014508:Urea; D003404:Creatinine; D004139:Dinitrofluorobenzene; D003402:Creatine Kinase; D052281:Creatine Kinase, Mitochondrial Form; D007791:Lactoylglutathione Lyase; D003401:Creatine; D019803:Glutathione Disulfide