Abstract
In the rats which received the transplantation of the ascites tumor, MTK-sarcoma III, the changes in contents of glycogen, RNA and DNA in the liver cells were investigated by means of a series of cytochemical and microspectrophotometric methods.
Gradual glycogen depletion was consistently observed from experiment to experiment in the liver cells of rats bearing tumor transplants. Every rat which died of tumor contained a very little amount of glycogen in their liver cells. The rate of the glycogen depletion of tumor-bearing animals exceedingly surpassed that of starved rats. It has remained unsolved in the present study whether the observed depletion of liver glycogen occurred in rats as a direct response to the enormous requirement of energy by tumor cells, or whether tumor transplants attacked hormonal glands of the host which control the glycogen storage in the liver. Whatever the causes may be, it is very likely that the glycogen depletion observed in the tumor-bearing rats may be attributable to the tumor transplants in hosts.
Contrary to the glycogen depletion, RNA (basophilia digestable by RNase) increased gradually with the prolonged existence of the tumor transplants. The increase in amount of RNA was observed both in the cytoplasm and in the nucleus. The thickening of the nuclear membrane and the hyperactivity of the nucleolus observed in the tumor animals seem to indicate the active participation of the nucleus in association with the accelerated production of RNA in the liver cells.
An increase of net DNA content (Feulgen-Schiff complex) took place in connection with an increase of the nuclear volume in liver cells of tumor-bearing animals during the period of the most active proliferation of the tumor. Its significance was discussed in relation to the DNA content of the nucleus.
Increased mitotic activity and dilatation of the liver sinusoids were also observed in livers of the rats bearing tumor transplants.
