Studies on swelling-shrinkage and oxidative phosphorylation of liver mitochondria of rat fed on 3'-methyl-4-dimethylaminoazobenzene

The swelling-shrinkage and oxidative phosphorylation of rat liver mitochondria affected by 3'-methy1-DAB feeding were observed in correlation with function by the method mentioned, and the following results were obtained: 1. By feeding 3'-methy1-DAB the swelling-shrinkage ability of rat liver mitochondria showed a remarkable alteration reducing in the amplitude. It reduced gradually during the days of feeding, reached the minimum value on 30th day and restored gradually thereafter (in Case 1). 2. ADP/O ratio also decreased by feeding the carcinogen reached the minimum point on 30th day and increased on 38th day showing the similar tendency in the decrease of the swelling-shrinkage amplitude (in Case 1). 3. The mitochondria from the hepatoma, which was induced by 3'-methy1DAB feeding, showed a lower amplitude in swelling-shrinkage with the dropped ADP/O ratio compared with those of mitochondria from liver tissue neighbouring the tumor. 4. The mechanism in the reduction of swelling-shrinkage ability has been discussed in the relation with fatty acid composition of mitochondria which is reported elsewhere. 5. From the above results it is deduced that lowered ability for swellingshrinkage with the reduced oxidative phosphorylation will be somehow related to the mechanism of cancer induction.