Levamisole circumvents inhibition of lymphocyte activation imposed by uremic serum.

Uremic serum inhibits thymidine incorporation of phytohemagglutinin-stimulated lymphocytes originating in normal individuals. In this study the effect of levamisole on such inhibition was investigated. Preincubation with a wide range of levamisole concentrations resulted in complete prevention of the inhibitory effect imposed by uremic serum on thymidine incorporation. We would like to suggest that uremic serum possibly inhibits thymidine incorporation of normal lymphocytes by imposing an abnormal cyclic GMP/cyclic AMP intracellular ratio, and that levamisole may restore this ratio to normal.