Effect of purine nucleosides on human leukocytes in normal conditions and in leukemias

: The degree of action of purine nucleosides (adenosine, deoxyadenosine (d-ado) and deoxyguanosine (d-gua] on peripheral blood leukocytes in leukemias has been shown to change, as estimated by their inhibition of the protein biosynthesis. The inhibitory effect of purines on lymphocytes of the CLL patients and on myeloid cells of patients is decreased as compared to the normal cells. On the contrary, blast cells in T-ALL and AML exhibit the increased sensitivity to d-gua and d-ado. The cytotoxicity of d-ado, as compared to that of other nucleosides, is markedly higher against both the normal and leukemic lymphoid and myeloid cells. The relationship between the differences in purine nucleoside action on the normal and leukemic cells and the peculiar features of the nucleotide metabolism in these cells is discussed.