Modulation of humoral response in rats by levamisole, mechlorethamine and sodium diethyldithiocarbamate.

The effects of levamisole (LMS) (2.5 mg/kg), mechlorethamine (MCHT) (5 or 600 micrograms/kg) and sodium diethyldithiocarbamate (DTC) (20 mg/kg) on primary humoral response of SRBC immunized rats were investigated. Each drug mentioned potentiates the primary humoral response to SRBC by increasing the number of plaque forming cells (PFC) and the level of anti-SRBC antibodies. Comparatively the strongest effect reflected in the increased quantity of PFC occurs after a single administration of the drugs, 48 h after antigen stimulation. The effect of DTC is twice lower than that of LMS or MCHT (5 micrograms/kg). Moreover, accelerated production of IgG (7S anti-SRBC antibodies) is a result of a single administration of LMS and MCHT (5 micrograms/kg) 72 h or 96 h after immunization or five days' DTC treatment at 24 hours intervals. MCHT administered at a dose of 600 micrograms/kg suppresses humoral response of the immunized rats both after a single dosage and five days' treatment at 24 hours intervals.