Contact hypersensitivity to disodium hexachloroplatinate in mice.

Complex platinum (Pt) compounds are known as occupational respiratory sensitizers whereas their role in skin exposure is unclear. In this study, both skin irritation and induction of contact hypersensitivity by halide Pt salts were characterized in mice. Repeated application of Na2[PtCl6] (5% in acetone) to both ears of naive BALB/c mice induced activation of the draining auricular lymph nodes. Flow cytometric analysis revealed a striking increase in the number of lymph node cells expressing proliferating cell nuclear antigen. In separate experiments, Na2[PtCl6] or acetone were applied only to the right ear of mice on 4-8 consecutive days and the animals were challenged on the left ear 6 da…