Morphology of mitochondria and cell respiration,pt.2.

With the purpose to elucidate the relation between the enzyme activity and the morphology of mitochondria the author carried out histochemical and biochemical investigations of cytochrome oxidase and succinic dehydrogenase activities of liver cells obtained at various intervals after the oral administration of CCl4, to male rats. And the data were compared with those reported in the first report. In the normal liver histochemically demonstrable cytochrome c oxidase activity and succinic dehydrogenase activity can be seen in parenchymal cells. In both cases the cells lying in the peripheral area show a more intense activities than those in the central part of liver lobules. The activity of cytochrome c oxidase falls markedly 5 to 6 hours after the CCl4, administration, while the activity of succinic dehydrogenase is retained almost at normal level for about 20 hours. Quantitative estimation of the succinic dehydrogenase activity of tissue homogenate revealed a transient rise in the activity 90 minutes after the CCl4, administration, and thereafter the values have been kept in almost normal level by 20 hours though a gradually fall has been seen in this period with a marked degree at 22nd hour. Taking the changes of minute structure occurring at each stage into consideration, which have been reported in the previous paper, the author concludes that the activity of succinic dehydrogenase is closely correlated with the maintenance of double membraneous structure of mitochondria, but the activity of cytochrome c oxidase is reduced by the swelling of mitochondria.