Further evidence of immunomodulatory effects of cimetidine.

The immunomodulatory effect of cimetidine was demonstrated both on human lymphocytes in vitro and in an experimental mice tumour model. Cimetidine increased the incorporation of tritiated thymidine into peripheral blood lymphocytes of healthy donors after nonspecific stimulation with PHA and Con A in vitro. Cimetidine prolonged the survival of mice bearing the syngeneic ascitic lymphoma EL-4. It had no cytotoxic effect on cells of ascitic lymphoma EL-4 in tissue culture.