Female mice received either cupravit or previcur at dose levels of 300 ppm and 1000 ppm, respectively, for 8 weeks. Humoral immune response was evaluated by measuring the plaque-forming cell (PFC) response and hemolysing antibody titers against sheep red blood cells (SRBCs), a T lymphocyte-dependent antigen. In addition, the hemagglutinating antibody titers against Escherichia coli lipopolysaccharide (LPS), a T cell-independent antigen, were determined. Both cupravit and previcur suppressed the PFC response by 74% and 78% of control values, respectively. The primary hemolysin antibody titers were reduced to 62% and 76% of control values, respectively. The hemagglutinating antibody titers were decreased to 66% and 77% of control values, respectively. Memory function was reduced as evidenced by inhibition of secondary hemolysin titers to SRBCs. Cell-mediated immunity was inhibited by both cupravit and previcur as evidenced by reduced delayed-type hypersensitivity (DTH) reaction to tuberculin to 77% and 76% of control values, respectively. Decreases in total leukocytic and lymphocytic counts were recorded together with histopathological changes in spleen and thymus gland of intoxicated animals.
Copyright 2001 Academic Press.