Evaluation of immune function in mice exposed to Ordram.

The potential effects that the thiocarbamate herbicide Ordram has on the immune system of mice was evaluated following 12 days of acute dosing by oral gavage. Dosages of Ordram ranging from 20 to 320 mg/kg/day had no consistent significant effects on a variety of immune parameters investigated. The immune parameters measured were the following: body and lymphoid organ weights; splenic natural killer (NK) cell activity; lymphoproliferative responses to B and T lymphocyte mitogens and allogeneic spleen cells in a one-way mixed lymphocyte reaction; and delayed-type hypersensitivity and antibody responses to sheep red blood cells (SRBC). The effects that the immunosuppressant cyclophosphamide has on these immune parameters was also examined. The results indicate that Ordram does not appear to affect key parameters of the immune system of mice under the conditions of exposure employed.