AbstractThe effects of sodium diethyldithiocarbamate (DTC) on humoral response to SRBC and restoration of the response impaired by a single cyclophosphamide dose (200 mg/kg) were tested on mice. Moreover, the effect of DTC (20 mg/kg) on thymocyte subpopulations was tested on non-immunized mice previously treated with cyclophosphamide.It was found that DTC (20 mg/kg) administered to the immunized mice enhanced humoral response to SRBC, which was reflected in the increased number of PFC and (7S) serum hemagglutinin titer. In contrast, partial restoration of the primary humoral response after DTC injection was observed in the mice administered a single cyclophosphamide dose. The effect of DTC was stronger after 6 days following cyclophosphamide injection, i.e. at the time when spontaneous restoration of T lymphocytes begins. In addition, it was found that DTC given to non-immunized mice treated with cyclophosphamide had a modulating effect on thymocyte subpopulations. Depending on the time of exposure to cyclophosphamide, DTC either increased the percentage of CD4 thymocytes or decreased the percentage of CDS, which subsequently led increased CD4/CD8 coefficient. DTC did not change the suppressing action of cyclophosphamide on the percentage of double-positive thymocytes.