Oxygen-dependent regulation of energy metabolism in ascites tumor cells by nitric oxide.
To understand the role of nitric oxide (NO) in the regulation of energy metabolism of tumor cells, its effect on the respiration and calcium homeostasis was examined with ascites hepatoma (AH130) cells under different oxygen tensions. NO reversibly inhibited the respiration and depolarized the membrane potential of AH130 cells in an oxygen-dependent manner; the inhibition was more marked at physiologically low oxygen concentrations than at its high tensions. NO reversibly decreased the cellular ATP levels and elevated the cytosolic calcium, particularly under low oxygen concentrations. Since the peritoneal cavity is fairly anaerobic, the results suggested that small amounts of NO generated in this compartment might strongly affect the energy metabolism and calcium homeostasis of tumor cells in vivo.
Nishikawa
M
M
Department of Biochemistry, Osaka City University Medical School, Japan.
Sato
E F
EF
Utsumi
K
K
Inoue
M
M
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D000968:Antimycin A / Q000494:pharmacology; D001201:Ascites; D001205:Ascorbic Acid / Q000494:pharmacology; D001692:Biological Transport / Q000187:drug effects; D002118:Calcium / Q000378:metabolism; D006528:Carcinoma, Hepatocellular / Q000473:pathology*; D004579:Electron Transport / Q000187:drug effects; D004734:Energy Metabolism / Q000502:physiology*; D004912:Erythrocytes / Q000502:physiology; D006454:Hemoglobins / Q000378:metabolism; D008113:Liver Neoplasms / Q000473:pathology*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008930:Mitochondria, Liver / Q000378:metabolism; D009368:Neoplasm Transplantation; D009569:Nitric Oxide / Q000502:physiology*; D010100:Oxygen / Q000502:physiology*; D010101:Oxygen Consumption / Q000187:drug effects; D051381:Rats; D011919:Rats, Inbred Strains; D012402:Rotenone / Q000494:pharmacology; D013386:Succinates / Q000494:pharmacology; D019802:Succinic Acid; D013772:Tetramethylphenylenediamine / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D006454:Hemoglobins; D013386:Succinates; D012402:Rotenone; D009569:Nitric Oxide; D000968:Antimycin A; D000255:Adenosine Triphosphate; D019802:Succinic Acid; D013772:Tetramethylphenylenediamine; D001205:Ascorbic Acid; D010100:Oxygen; D002118:Calcium