The effects of zeranol, an anabolic agent, on the serum immunoglobulins of rabbits immunized with B.19 brucellosis vaccine.

Rabbits were immunized with strain 19 antibrucella vaccine and repeatedly administered zeranol subcutaneously (total dose 10 mg in 28 days). The antibody response was followed up for 14 weeks. The following effects were observed: a) an increase in serum proteins during the period of zeranol treatment; b) increases of the agglutinating and, later, of the complement fixing activity, probably caused by an enhanced antibody avidity; c) an increased production and persistence of IgM (19 S).