Purine metabolism in splenocytes and thymocytes of various mammalian species.

Abstract

In man ADA (adenosine deaminase) deficiency is associated with severe combined immunodeficiency and deficiency of PNP (purine nucleoside Phosphorylase) with a severe T-cell dysfunction. The ADA deficiency was found in all tissues of affected children (1), but the lymphoid tissues showed relatively the lowest levels. Marked differences were reported in activities of ADA and PNP between various types of rat lymphoid cells and between cells of various stages of fetal T-cell differentiation (2,3). Jackson et al, (4) reported marked differences in activities of ADA and AK (adenosine kinase) between various rat tissues. Since the development of immune function enters a critical phase at birth, we measured the activities of ADA, PNP and AK in thymocytes and splenocytes of rats of 0-423 days. We also measured the activities of these enzymes in thymocytes and splenocytes of man, horse, pig, sheep and mouse, since we previously observed marked differences in purine metabolism in PBL (peripheral blood lymphocytes) of these species (5).