肝Catalase活性に関する研究 第2編 ラッテDAB肝癌発生前後に於ける肝Catalase活性の変化に就て

In the first report the author described that the activity of liver catalase dropped markedly in the tumor-bearing individuals and moderately in some diseases like nephrosis uremia and othes. In this paper the author shows the experimental results carried on the liver of rats fed D.A.B. Feeding of D.A.B. for 6 weeks has raised the liver catalase activities extremely as high as about two times those of normal animals. Even in the liver developing tumors 4-5 months after D.A.B. feeding, the catase activities are found to be still as high as 2.4 times of normal level, though the tumor tissues themselves show an extremely lowered activity with some differences between the different types of tumors. Rather low levels of activity are found in the tumor developing as a mass with the expansive growth, 13 per cent of the normal level in mean value, comparing to those developing to the infiltrative pattern 130%. This will be due to the contamination of the normal liver cells in the latter, as the tumor tissues taken for the estimation can not be separated completely from the surrounding normal tissues. These results show that the catalase activity of liver is raised by affecting with D.A.B. showing the level as almost 2.5 times as high as that of normal rat liver. This level is kept in the stage of the development of tumors, but an extremely lowered level in tumor tissues. Any gradual changes of catalase activity from the D.A.B. affected tissues to the tumors can not be found showing occurrence of spontaneous change in the catalase activity by tumorization of cells.