The mouse ear edema: a quantitatively evaluable assay for tumor promoting compounds and for inhibitors of tumor promotion.

The induction of edema in the mouse ear has been established as a reliable in vivo assay for tumor promoting compounds and for inhibitors of tumor promotion. Apparently all skin tumor promoting compounds induce an edema, and all inhibitors of a tumor promoter-induced edema are most likely inhibitors of skin tumor promotion. No exception to this rule has been found as yet. Besides the application of this assay in the screening of compounds, the assay allows comparison of various compounds (e.g. complete and incomplete tumor promoters) with respect to their kinetics and dosage response in the induction of edema.