Suppression of footpad reaction in mice by anthralin.

In the preceding papers, we showed that the treatment of BALB/c mice with 12-O-tetradecanoylphorbol 13-acetate (TPA), a typical tumor promoter, suppressed footpad reaction (FPR) against sheep red blood cells (SRBC) temporarily but that this effect became lasting when TPA was administered to mice which had been treated with 7,12-dimethyl[a]-anthracene (DMBA), a typical tumor initiator, and that the effect of DMBA and TPA was caused by the induction of antigen-nonspecific T suppressor cells. In this work, we studied the effect of anthralin, a tumor promoter which has not the structure of phorbol ester, on FPR of BALB/c mice against SRBC. Painting of anthralin (80 nmol) suppressed FPR continuously (more than 7 days) unlike that of TPA. However, when anthralin was administered for 7 days following the treatment with 400 nmol of DMBA, the suppressive effect could be transferred with Thy-1 and Lyt-2 positive spleen cells whereas the suppressive effect by the painting of anthralin only for 7 days could not be transferred with the spleen cells.