title: Release from the Crabtree effect by hypoxic cell radiosensitizers.
abstract: The Crabtree effect can be observed when the O2 consumption of tumour cells or of mammalian cells grown in culture is measured in physiological medium containing glucose. The effect of 2 hypoxic cell radiosensitizers, misonidazole and NDPP, on the O2 consumption of Ehrlich ascites tumour cells was compared in media with and without glucose. A stimulatory effect on O2 consumption was found for 5--20mM misonidazole as well as for 0.5mM NDPP, both in media containing 10(-2)M glucose. Thus glucose induced a Crabtree effect in Ehrlich tumour cells, expressed as 38--45% inhibition of O2 consumption relative to that in the same medium without glucose. The stimulatory effect of misonidazole and NDPP on O2 utilization in medium with glucose undoubtedly appeared as a release from the Crabtree effect.
mesh_terms: D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism*; D002478:Cells, Cultured; D005947:Glucose / Q000494:pharmacology*; D051379:Mice; D008920:Misonidazole / Q000494:pharmacology*; D009574:Nitro Compounds; D009593:Nitroimidazoles / Q000494:pharmacology*; D010101:Oxygen Consumption; D011427:Propiophenones / Q000494:pharmacology*; D011838:Radiation-Sensitizing Agents / Q000494:pharmacology*
chemical_list: D009574:Nitro Compounds; D009593:Nitroimidazoles; D011427:Propiophenones; D011838:Radiation-Sensitizing Agents; C021225:4-nitro-3-dimethylaminopropiophenone; D008920:Misonidazole; D005947:Glucose