METABOLIC POOL OF PURINE COMPOUNDS IN MOUSE-BLOOD ERYTHROCYTES DURING GROWTH OF IMPLANTED TUMORS

Much attention has recently been paid to the study of purine (and also pyrunidine) metabolosm in circulating erythrocytes of animals and man in various pathological states [7]. While performing the function of transport of purine metabolites in the body, erythrocytes constitute an effective system of communication between tissues requiring a supply of free nucleosides and nitrogenous bases for subsequent reutilization in kinase and phosphoribosyl transferase reactions [6]. The development of tumors in vivo is accompanied by significant changes in nuclear metabolism both in the tumor itself and in distant tissues [5]. For example, in immunocompetent cells, in which purine metabolism plays a key role in reactions of differentiation, maturation, and proliferation of lymphocytes [3], profound changes in activity of the enzymes of purine metabolism correpond to different stages of growth of a hepatoma [4]. Recognizing the transport functions of erythrocytes in relation to purine compounds and also various kinds of disturbance of purine metabolism in a tumor-bearing organism, it was considered important to study the character of changes in the pool of purine metabolites in circulating blood erythrocytes during growth of implanted tumors.