Oxidative Stress on the Nuclei as a Factor Regulating the Susceptibility of Spontaneous Lung Tumorigenesis in Mice

We investigated of the relation between oxidative stress on nuclei and spontaneous lung tumorigenesis in mice. An unsaturation index of fatty acids, the levels of active oxygen formed and thiobarbituric acid reactive substances in pulmonary nuclei of A/J strain were higher than those in the nuclei of C3H/He and C57BL/6Cr strains. In vitro active oxygen-dependent DNA nicking capacity via nuclear electron-transferring systems in lungs of A/J strain was also stronger than those in the lungs of the other two strains, while the nuclear α-tocopherol level in the A/J strain was lowest of the three. The differences of these parameters in the lungs among the three strains were in agreement with the strain differences of the lung tumorigenesis. These results suggest that the spontaneous development of lung tumors relates to some degree on the level of oxidative stress on the nuclei.