Gudz T I, Pandelova I G, Novgorodov S A
Department of Biophysics, Biological Faculty, Moscow State University, Russia.
Radiat Res. 1994 Apr;138(1):114-20.
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.
研究了X射线照射对大鼠胸腺细胞呼吸作用的影响。用6 - 10 Gy剂量照射细胞1小时后，观察到氧气摄取速率增加。辐射诱导的呼吸增加可被线粒体ATP合酶抑制剂寡霉素阻断，提示其受细胞质ATP周转率增加的调控。呼吸的刺激与线粒体电子传递酶活性或内膜通透性的变化无关。筛选了几种利用ATP的过程的抑制剂，以研究它们对基础呼吸速率和辐射反应的影响。在照射的胸腺细胞中，观察到哇巴因、La3 +和环己酰亚胺对呼吸抑制的增强作用。这些结果表明，辐射诱导的呼吸刺激是由于离子稳态和蛋白质合成的变化。研究表明，X射线照射的效应与非蛋白硫醇的氧化还原状态无关，且与脂质过氧化某些产物的可检测变化无关。辐射诱导的超氧化物歧化酶活性降低表明自由基参与了辐射的有害作用。
