Role of orthophosphate concentration in the regulation of ribose phosphate synthesis and purine metabolism in Ehrlich ascites tumor cells

1977 ◽  
Vol 55 (8) ◽  
pp. 834-840 ◽  
Author(s):  
Jerzy Barankiewicz ◽  
Mary L. Battell ◽  
J. Frank Henderson
Keyword(s):  
Tumor Cells ◽  
Purine Metabolism ◽  
Ehrlich Ascites Tumor ◽  
Ehrlich Ascites Tumor Cells ◽  
Ascites Tumor ◽  
Phosphoribosyl Pyrophosphate ◽  
Ribose Phosphate ◽  
Ehrlich Ascites ◽  
In Cells

Concentrations of intracellular orthophosphate were determined in Ehrlich ascites tumor cells incubated with glucose, inosine, or uridine in media of different orthophosphate concentration. The effects of orthophosphate concentration on the accumulation of lactate and of phosphoribosyl pyrophosphate and on concentrations of ribose 1-phosphate and ribose 5-phosphate in tumor cells incubated with glucose were also determined. Both the phosphorolysis of inosine and the rate of catabolism of ATP in cells incubated with 2-deoxyglucose were also influenced by the orthophosphate concentration of the medium.

Effects of Actinomycin D on Purine Ribonucleotide Metabolism in Ehrlich Ascites Tumor Cells In Vitro

1974 ◽  
Vol 52 (3) ◽  
pp. 263-267 ◽  
Author(s):  
Floyd F. Snyder ◽  
J. Frank Henderson
Keyword(s):  
Tumor Cells ◽  
Actinomycin D ◽  
De Novo ◽  
Acid Synthesis ◽  
Purine Metabolism ◽  
Ehrlich Ascites Tumor ◽  
Ehrlich Ascites Tumor Cells ◽  
Ascites Tumor ◽  
Ehrlich Ascites

Actinomycin D treatment of Ehrlich ascites tumor cells in vitro causes slight to moderate inhibition of purine ribonucleotide synthesis de novo and from purine bases, and strong inhibition of inosinate dehydrogenase activity. These effects have the same dose–response relationship as inhibition of RNA synthesis by this drug. Daunomycin has similar effects on purine metabolism at a concentration that substantially inhibits nucleic acid synthesis. Actinomycin D treatment leads to elevated intracellular concentrations of ATP and GTP, and the effects of this drug on purine metabolism are believed to be mediated by these purine ribonucleoside triphosphates.

Relative importance of alternative pathways of purine nucleotide biosynthesis in Ehrlich ascites tumor cells in vivo

1976 ◽  
Vol 54 (4) ◽  
pp. 341-349 ◽  
Author(s):  
Camilla M. Smith ◽  
J. Frank Henderson
Keyword(s):  
Tumor Cells ◽  
Ehrlich Ascites Tumor ◽  
Relative Importance ◽  
Purine Nucleotide ◽  
Ehrlich Ascites Tumor Cells ◽  
Ascites Tumor ◽  
Alternative Pathways ◽  
Ehrlich Ascites ◽  
In Cells

Several alternative pathways of purine nucleotide synthesis coexist in cells and the relative importance of each pathway for maintaining purine nucleotide concentrations in cells has been studied. Specific inhibitors were used to block these synthetic routes in Ehrlich ascites tumor cells in vivo and the effect of inhibiting each pathway was evaluated by measuring intracellular purine nucleotide concentrations by high-speed liquid chromatography. The results of this study indicate that adenosine triphosphate and guanosine triphosphate concentrations of Ehrlich ascites tumor cells are maintained primarily by purine biosynthesis de novo although other pathways do make significant contributions.

ENHANCEMENT OF RIBONUGLEOSIDE SYNTHESIS IN EHRLICH ASCITES TUMOR CELLS BY ARSENATE AND IODOACETATE

1965 ◽  
Vol 43 (10) ◽  
pp. 1693-1700 ◽  
Author(s):  
A. R. P. Paterson ◽  
A. I. Simpson
Keyword(s):  
Tumor Cells ◽  
Incubation Medium ◽  
Ehrlich Ascites Tumor ◽  
Ehrlich Ascites Tumor Cells ◽  
Ascites Tumor ◽  
Rapid Exchange ◽  
Ribose Phosphate ◽  
Ehrlich Ascites ◽  
Lactate Formation

Ehrlich ascites tumor ceils in vitro synthesize ribonucleosides, which appear mainly in the incubation medium, by the transfer of ribose from a donor ribonucleoside to an acceptor base. In the present study, it was found that the rates of synthesis of inosine and uridine in this system were markedly enhanced in the presence of arsenate or iodoacetate. The exchange of isotope between extracellular inosine and hypoxanthine-8-C14 was similarly enhanced by arsenate, but the more rapid exchange between uridine and uracil-2-C14 was unaffected. Arsenate did not cause changes in the rates of uridine breakdown that would account for the enhanced rate of nucleoside synthesis and did not promote the release of nucleoside-synthesizing enzymes from the tumor cells into the incubation medium. Because lactate formation during the uridine-supported synthesis of inosine was markedly inhibited by arsenate and iodoacetate, the increase in ribonucleoside synthesis appears to be indirect and to be related to inhibition of ribose phosphate catabolism.

Inhibition of glycolysis in Ehrlich ascites tumor cells incubated with formimino-L-glutamate

1969 ◽  
Vol 47 (4) ◽  
pp. 419-422 ◽  
Author(s):  
Lydia J. Fontenelle ◽  
J. Frank Henderson
Keyword(s):  
Tumor Cells ◽  
De Novo ◽  
Ehrlich Ascites Tumor ◽  
Ehrlich Ascites Tumor Cells ◽  
Ascites Tumor ◽  
Phosphoribosyl Pyrophosphate ◽  
Triose Phosphate ◽  
Glucose Inhibition ◽  
Ehrlich Ascites ◽  
Inhibition Of Glycolysis

Incubation of tumor cells with formiminoglutamate leads to inhibition of lactate synthesis from glucose, inhibition of phosphoribosyl pyrophosphate synthesis, and inhibition of purine ribonucleotide synthesis de novo and from purine bases. Lactate synthesis from inosine was increased. These effects may result from inhibition of triose phosphate isomerase by a metabolite of formiminoglutamate.

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