title: Changes in delayed hypersensitivity reaction in mice exposed to O3.
abstract: BALB/c mice were continuously exposed to 0.8 ppm O3 for 1, 3, 7, and 14 days. Ozone exposure suppressed the delayed hypersensitivity (DH) reaction to sheep red blood cells (SRBC). The maximum effect was seen after 7 days of exposure. To estimate the suppression of the DH reaction by O3 exposure, the numbers of lymphocytes in thymus and blood of exposed mice were compared with those of control mice. A decrease in the numbers of lymphocytes in both thymus and blood was observed in O3-exposed mice. The percentage of T and B lymphocytes in blood of exposed mice was the same as that in blood of control mice. These results suggest that 0.8 ppm O3 exposure affects the T lymphocytes required for DH reactions.
mesh_terms: D000818:Animals; D006968:Hypersensitivity, Delayed / Q000276:immunology; D007111:Immunity, Cellular / Q000187:drug effects*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010126:Ozone / Q000633:toxicity*; D013601:T-Lymphocytes / Q000187:drug effects
chemical_list: D010126:Ozone