The effects of
tuftsin and
steroids (methyl
prednisolone) on the induction of disrupted plasma
proteinase regulation in mice bearing the
B16 melanoma or treated with Corynebacterium parvum was investigated.
Tuftsin treatment inhibited
tumor progression only if treatment was started at the time of
tumor transplantation. However,
tuftsin inhibited the development of
splenomegaly in mice with established
tumors. In contrast,
tuftsin did not influence either the induction of elevated plasma
proteinase activity or the activity in plasma from animals with established
tumors. Treatment of mice with high, anti-inflammatory, doses of
steroid (20 mg/kg/day) partially inhibited
tumor progression, inhibited the induction of
splenomegaly, but did not inhibit the induction of disrupted plasma
proteinase regulation. Likewise,
steroid treatment did not suppress the induction of elevated plasma
proteinase activity following treatment of mice with C. parvum. Thus the induction of elevated plasma
proteinase activity, previously demonstrated to be a host regulated phenomenon, is resistant to regulation by this anti-inflammatory
drug and likely not a component of the anti-
tumor response. These findings raise the possibility that this phenomenon results from the interaction of activated RES elements with components of the plasma
proteinase cascades.