Female mice received either cupravit or previcur at dose levels of 300 ppm
and 1000 ppm, respectively, for 8 weeks. Humoral immune response was evalua
ted by measuring the plaque-forming cell (PFC) response and hemolysing anti
body titers against sheep red blood cells (SRBCs), a T lymphocyte-dependent
antigen. In addition, the hemagglutinating antibody titers against Escheri
chia coil lipopolysaccharide (LPS), a T cell-independent antigen, were dete
rmined. Both cupravit and previcur suppressed the PFC response by 74% and 7
8% of control values, respectively. The primary hemolysin antibody titers w
ere reduced to 62% and 76% of control values, respectively. The hemagglutin
ating antibody titers were decreased to 66% and 77% of control values, resp
ectively. Memory function was reduced as evidenced by inhibition of seconda
ry 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, respectivel
y. Decreases in total leukocytic and lymphocytic counts were recorded toget
her with histopathological changes in spleen and thymus gland of intoxicate
d animals. (C) 2001 Academic Press.