Suppression of the formation of megamitochondria by scavengers for free radicals.
In the present study we have attempted to suppress the formation of megamitochondria by scavengers for free radicals since conditions for the formation of megamitochondria are often intimately related to the generation of free radicals. We employed three different experimental conditions to induce megamitochondria in the liver: ethanol, hydrazine and chloramphenicol (CP). Scavengers for free radicals tested were: alpha-tocopherol, coenzyme Q10(CoQ10) and 4-hydroxy-2,2,6,6-tetramethyl-piperidine-1-oxyl(4-OH-TEMPO). Allopurinol (AP), a xanthine oxidase inhibitor, was also tested. Results obtained were as follows. (1) Changes observed in the liver of animals treated with ethanol, hydrazine or CP were: formation of megamitochondria; decreases in the body weight and the weight of the liver; remarkable increases in the level of lipid peroxidation; increases in the activity of xanthine oxidase. (2) 4-OH-TEMPO was most effective in improving these changes. A mechanism of the formation of megamitochondria is proposed stressing the role of free radicals in the mechanism.
Wakabayashi
T
T
Department of Cell Biology and Molecular Pathology, Nagoya University School of Medicine, Japan.
Adachi
K
K
Matsuhashi
T
T
Wozniak
M
M
Antosiewicz
J
J
Karbowsky
M
M
D000493:Allopurinol / Q000494:pharmacology; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002701:Chloramphenicol / Q000494:pharmacology; D003067:Coenzymes; D003497:Cyclic N-Oxides / Q000494:pharmacology; D003864:Depression, Chemical; D004791:Enzyme Inhibitors / Q000494:pharmacology; D000431:Ethanol / Q000494:pharmacology; D016166:Free Radical Scavengers / Q000494:pharmacology*; D006834:Hydrazines / Q000494:pharmacology; D015227:Lipid Peroxidation; D008297:Male; D008315:Malondialdehyde / Q000032:analysis; D008561:Membrane Fusion / Q000187:drug effects; D008930:Mitochondria, Liver / Q000187:drug effects* / Q000378:metabolism / Q000648:ultrastructure; D011687:Purines / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D013113:Spin Labels; D014451:Ubiquinone / Q000031:analogs & derivatives / Q000494:pharmacology; D014810:Vitamin E / Q000494:pharmacology; D014969:Xanthine Oxidase / Q000037:antagonists & inhibitors
D003067:Coenzymes; D003497:Cyclic N-Oxides; D004791:Enzyme Inhibitors; D016166:Free Radical Scavengers; D006834:Hydrazines; D011687:Purines; D013113:Spin Labels; D014451:Ubiquinone; D014810:Vitamin E; C029424:hydrazine; D000431:Ethanol; D008315:Malondialdehyde; D000493:Allopurinol; D002701:Chloramphenicol; D014969:Xanthine Oxidase; C024989:coenzyme Q10; C001803:tempol