Glutathione metabolism during Yoshida ascites sarcoma growth.

Glutathione (GSH) metabolism and protein synthesis were observed over a period of about two weeks in Yoshida ascites sarcoma and intracellular concentration relative to days 7, 10 and 13 assumed as 'markers' of different stages of tumor development. During this period the decrease in rate of cell proliferation was followed by decrease in protein synthesis, GSH, oxidized glutathione (GSSG), adenosine triphosphate (ATP), glutathione-S-transferase (GSH-S-transferase) and gamma-glutamyl-cysteine synthatase (gamma-GCS); by increase in glutathione-peroxidase (GSH-peroxidase); while glutathione-reductase (GSH-reductase) and glucose-6-phosphate-dehydrogenase (G-6-PD) remained unchanged. In relation to growth curve of the tumor, GSH concentration was very high up to day 7 (logaritmic phase), decreased till quantity similar to that of corresponding normal cells up to day 10 (plateau phase) and on day 13 was significantly smaller. Correlation between high concentration of GSH in tumor cells and their survival and proliferation after intraperitoneal implantation is discussed.