Regulation of glutathione metabolism in Ehrlich ascites tumour cells.
Glutathione metabolism was studied in cancer cells during the growth of an Ehrlich ascites tumour. GSH, but not GSSG, content decreases when cell proliferation and the rate of protein synthesis in the tumour decrease. This change correlates with a decrease in the rate of GSH synthesis and an increase in glutathione peroxidase and glutathione S-transferase activities. Glutathione efflux from tumour cells seems to co-ordinate with the rate of GSH synthesis. Cysteine, and not methionine, promotes GSH synthesis in tumour cells. However, changes in the rate of GSH synthesis are not due to limitations in the supply of blood cysteine or to changes in the intracellular amino acid pool of the cancer cells. Our data suggest that changes in protein metabolism accompanying tumour growth in vivo can modulate glutathione content in cancer cells.
Estrela
J M
JM
Departamento de Fisiología, Universidad de Valencia, Spain.
Hernandez
R
R
Terradez
P
P
Asensi
M
M
Puertes
I R
IR
Viña
J
J
D000111:Acetylcysteine / Q000494:pharmacology; D000596:Amino Acids / Q000097:blood; D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000378:metabolism* / Q000473:pathology; D002455:Cell Division; D002478:Cells, Cultured; D005954:Glucosephosphate Dehydrogenase / Q000378:metabolism; D005978:Glutathione / Q000031:analogs & derivatives / Q000378:metabolism*; D019803:Glutathione Disulfide; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000378:metabolism*; D008297:Male; D008715:Methionine / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D051381:Rats; D012016:Reference Values; D013347:Subcellular Fractions / Q000378:metabolism
D000596:Amino Acids; D008715:Methionine; D005954:Glucosephosphate Dehydrogenase; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D005978:Glutathione; D019803:Glutathione Disulfide; D000111:Acetylcysteine