Glucose decreases respiratory control ratio in EL-4 tumor cells.
EL-4 ascites thymoma cells are shown to have high aerobic glycolysis and decreased Pasteur effect. At the same time, glucose produces a much smaller inhibitory effect on cell respiration (Crabtree effect) than in Ehrlich ascites carcinoma (EAC) cells. In intact EL-4 cells, the respiratory control ratio (RCR) was found to be 6.2 with endogenous substrates and 8.0 with glutamine. Glucose decreased the RCR to 3.2, by stimulating the state 4 respiration. In rat thymocytes and EAC cells, such an effect of glucose was absent (RCR of 7.0 and 7.2, respectively). It is suggested that in EL-4 tumor cells, the high aerobic glycolysis and small Crabtree effect may be due to glucose-induced 'uncoupling' of oxidation and phosphorylation.
Gabai
V L
VL
Institute of Medical Radiology, Russian Academy of Medical Sciences, Obninsk.
D000818:Animals; D005260:Female; D005947:Glucose / Q000494:pharmacology*; D010085:Oxidative Phosphorylation / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects*; D051381:Rats; D017208:Rats, Wistar; D013945:Thymoma / Q000378:metabolism; D013953:Thymus Neoplasms / Q000378:metabolism; D014407:Tumor Cells, Cultured
D005947:Glucose