Stimulation of Respiration in Rat Thymocytes Induced by Ionizing Radiation

• Published in: Radiation research 1994-04, Vol.138 (1), p.114-120
• Main Authors: Gudz, Tatyana I., Pandelova, Iovanna G., Novgorodov, Sergei A.
• Format: Article
• Language: English
• Subjects: 550200 > Biochemistry; ACID ANHYDRASES; Analysis of Variance; ANIMAL CELLS; Animals; ANTI-INFECTIVE AGENTS; ANTIBIOTICS; Apoptosis; ATP-ASE; BASIC BIOLOGICAL SCIENCES; BIOLOGICAL EFFECTS; BIOLOGICAL RADIATION EFFECTS; CARBOHYDRATES; CARDIAC GLYCOSIDES; CARDIOTONICS; CARDIOVASCULAR AGENTS; Cells, Cultured; CYCLOHEXIMIDE; Cycloheximide - pharmacology; Dose-Response Relationship, Radiation; DRUGS; ELECTROMAGNETIC RADIATION; ENZYME ACTIVITY; ENZYME INHIBITORS; ENZYMES; FUNGICIDES; Glutathione Peroxidase - metabolism; Glutathione Peroxidase - radiation effects; GLYCOSIDES; HYDROLASES; Ionizing radiation; IONIZING RADIATIONS; Irradiation; Kinetics; Lanthanum - pharmacology; Lipid Peroxidation - radiation effects; Lipids; Male; Masoprocol - pharmacology; Oligomycins; Oligomycins - pharmacology; ORGANIC COMPOUNDS; OUABAIN; Ouabain - pharmacology; OXIDOREDUCTASES; Oxygen; Oxygen Consumption - drug effects; Oxygen Consumption - radiation effects; PESTICIDES; PHOSPHOHYDROLASES; PROTEINS; RADIATION EFFECTS; RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT; RADIATIONS; Rats; Rats, Wistar; RESPIRATION; Rotenone - pharmacology; SOMATIC CELLS; STIMULATION; STROPHANTHINS 560150 > Radiation Effects on Animals; Sulfhydryl Compounds - analysis; SUPEROXIDE DISMUTASE; Superoxide Dismutase - metabolism; Superoxide Dismutase - radiation effects; Superoxides; T-Lymphocytes - drug effects; T-Lymphocytes - metabolism; T-Lymphocytes - radiation effects; Thiobarbituric Acid Reactive Substances - analysis; THYMOCYTES; Thymus Gland - metabolism; Thymus Gland - radiation effects; X RADIATION; X-Rays
• ISSN: 0033-7587; 1938-5404
• DOI: 10.2307/3578854

The effect of X irradiation on the respiration of rat thymocytes was studied. An increase in the rate of O2 uptake was observed 1 h after cells were irradiated with doses of 6-10 Gy. The radiation-induced increase in respiration could be blocked by oligomycin, an inhibitor of mitochondrial ATP synthase, suggesting control by increased cytoplasmic ATP turnover. The stimulation of respiration was not associated with changes in the activity of mitochondrial electron transfer enzymes or permeability of the inner membrane. Several inhibitors of processes which used ATP were screened for their effects on the basal respiration rate and on the radiation response. In irradiated thymocytes, an enhancement of inhibition of respiration by ouabain, La3+ and cycloheximide was observed. These results indicate that the radiation-induced stimulation of respiration is due to changes in ion homeostasis and protein synthesis. The effect of X irradiation was shown to be independent of the redox status of nonprotein thiols and was not associated with detectable changes in some products of lipid peroxidation. The radiation-induced decrease in activity of superoxide dismutase suggests free radical involvement in deleterious effects of radiation.