Objective To investigate the radiation effect on mitochondria of the mouse liver in vivo. Methods Livers of BALB/c mice were squeezed out through openings cut on the upper abdomen and radiation doses were delivered ...Objective To investigate the radiation effect on mitochondria of the mouse liver in vivo. Methods Livers of BALB/c mice were squeezed out through openings cut on the upper abdomen and radiation doses were delivered only to the livers. Radiation effects on the structure and function of liver mitochondria were evaluated from both respiratory control ratio (RCR) and ADP/O (adenosine 5' diphosphate/oxygen) ratio supported by two substrates, succinate and glutamate/malate mixtures.Results The data showed that both state 3 and state 4 respiratory rates were significantly decreased concomitantly with the increase of radiation dose up to 20 Gy. Succinate supported, but not glutamate/malate supported, respiratory control ratio, was also decreased with the increase of radiation dose. ADP/O ratios measured from the support of both succinate and glutamate/malate were not changed by γ radiation. This differential radiation damage indicated that respiratory control ratio was more vulnerable to radiation than oxidative phosphorylation.Conclusions Although the functional integrity of ATP synthetic machinery of the mitochondria was not perturbed by ionizing radiation under 20 Gy, the structural integrity of mitochondrial membrane might be affected by ionizing radiation at a dose dependent manner.展开更多
文摘Objective To investigate the radiation effect on mitochondria of the mouse liver in vivo. Methods Livers of BALB/c mice were squeezed out through openings cut on the upper abdomen and radiation doses were delivered only to the livers. Radiation effects on the structure and function of liver mitochondria were evaluated from both respiratory control ratio (RCR) and ADP/O (adenosine 5' diphosphate/oxygen) ratio supported by two substrates, succinate and glutamate/malate mixtures.Results The data showed that both state 3 and state 4 respiratory rates were significantly decreased concomitantly with the increase of radiation dose up to 20 Gy. Succinate supported, but not glutamate/malate supported, respiratory control ratio, was also decreased with the increase of radiation dose. ADP/O ratios measured from the support of both succinate and glutamate/malate were not changed by γ radiation. This differential radiation damage indicated that respiratory control ratio was more vulnerable to radiation than oxidative phosphorylation.Conclusions Although the functional integrity of ATP synthetic machinery of the mitochondria was not perturbed by ionizing radiation under 20 Gy, the structural integrity of mitochondrial membrane might be affected by ionizing radiation at a dose dependent manner.
