Stimulatory effect of low doses of mechlorethamine on humoral response of ovalbumin-immunized rabbits--comparison with levamisole.

The effect of low doses of mechlorethamine (1-10 micrograms/kg) and levamisole (2.5 mg/kg) on humoral response of rabbits immunized twice with ovalbumin (0.1 mg/kg) was compared. It was shown that mechlorethamine given in a dose of 5 or 10 micrograms/kg potentiates the increase in the level of serum anti-ovalbumin hemagglutinins; this increase is induced both after the first and the second (after 14 days) antigen administration. Levamisole acted similarly but with much lower efficiency.