[Kinetics of degradation and resynthesis of the adenine-nucleotide pool in tumor cells].

Starting from the assumption that tumor cells constantly experience transient ischemia and anoxia, and that this results in metabolic stress which is reflected above all, on the concentration of ATP, ADP and AMP, in other words, the adenine nucleotide pool (AdN), the aim of our research was to study the degradation and resynthesis kinetics of that pool on two types of malignant cells. All experiments were conducted in vitro with cells of the transplantable tumors of Ehrlich's ascitic carcinoma and the AS 30D hepatoma, and metabolite analyses were carried out enzymatically or by way of the HPLC chromatography method. It was found that immediately after the setting on of anoxia, there comes not only to a fall in ATP, but also to a fall in the complete adenine nucleotide pool for about 50%. The further maintenance of anaerobiosis does not have a significant influence on the AdN pool. The adenine nucleotide pool resynthesis is very rapid in the examined cells, and in the presence of glutamine and inosine, there comes to an occurrence of its significant growth. Evidence is given that the resynthesis in Ehrlich's ascitic carcinoma cells is made possible through the purine nucleotide cycle, which probably brings about the intensive glutamine oxidation and aspartate production, while in the AS 30D hepatoma cells it develops by means of adenosine kinase. The AS 30D hepatoma cells maintain a high ATP level in the absence of oxygen for a long time, provided that iodine-acetate is not added, which points to the fact that they have some other kind of energetic reserve aside from ATP.(ABSTRACT TRUNCATED AT 250 WORDS)