Different effects of dimethylbenz(alpha)anthracene and tetradecanoylphorbol acetate on differentiation of mast cells in the skin of mice.

The effects of the application of 7,12-dimethylbenz(alpha)anthracene (DMBA) and 12-O-tetradecanoyl-phorbol-13-acetate (TPA) on the differentiation of tissue mast cells were investigated. Giant granules of beige (C57BL/6-bgJ/bgJ, Chédiak-Higashi syndrome) mice were used to distinguish different populations of mast cells. In the normal C57BL/6 mice that had been irradiated and injected with bone marrow cells of beige C57BL/6 mice (bgJ/bgJ leads to +/+ chimeras), mast cells in the skin remained normal in type and mast cell precursors in the bone marrow and peripheral blood were of the beige type. When DMBA was painted onto the skin of such bgJ/bgJ leads to +/+ chimeras, the number of beige mast cells increased, but the number of normal mast cells did not change. On the other hand, the number of both normal and beige mast cells increased when TPA was applied to the bgJ/bgJ leads to +/+ chimeras. Autoradiographic study showed that beige mast cells proliferated more than normal mast cells after DMBA applications, whereas the proliferations was comparable in both types of mast cells after TPA applications. The present results indicate that the effects of DMBA applications on differentiation of mast cells are different from those of TPA applications.