[Changes in purine metabolism and in the immune response in the thymic and splenic lymphocytes of C3HA mice during chemical hepatocarcinogenesis].

The activities of adenosine deaminase, purine nucleoside phosphorylase, membrane 5'-nucleotidase and DNA content in thymus and spleen lymphocytes as well as the immune function of T and B lymphocytes of the spleen of C3HA mice with o-AAT-induced hepatomas were studied 1, 3 weeks and 3, 8, 12 months after o-AAT treatment was instituted. In the early stages of the hepatocarcinogenesis (up to 3 months), the elevation of the activity of all the enzymes and DNA content in thymocytes and T and B lymphocytes was observed. These changes coincided with the enhancement of the immune responses that manifested in the increased content of PFC, EA-RFC and high response to PHA and Con A. In the late stages, the decreased activities of purine nucleosides and nucleotide metabolizing enzymes correlated with disturbances of lymphocyte differentiation and lowering of the host immune response.