| Objective:For a long time, with the rapid social and economic development of China, people are increasing their demands for the good quality of life. Indoor decoration has gradually become the most important means to improving living standards and quality of life, resulting increasingly severe indoor air pollution. Indoor air pollution has become one of the major factors threatening public health. As the most common indoor air pollutants, formaldehyde and trichloroethylene high toxicity and frequently with high concentrations coexist in the interior. Therefore, this study by static inhalation of gaseous formaldehyde, trichloroethylene poisoning in mice to study the toxic effects of formaldehyde and trichloroethylene separated or both on the immune system of mice and on the lipid peroxidation of immune organs, aimed to investigate the gaseous formaldehyde, trichloroethylene separate and combined injury effects on immune system in mice and its mechanism of action, and provide scientific basis for the indoor sanitation standard of formaldehyde and trichloroethylene. Methods:Choice healthy clean Kunming mice 108(male and female half). According to the requirements of the 3×3 factorial design, the mice were randomly divided into 9 groups by sex. With 50 L canister to ark for the static type suction canister, making the mice exposing to different concentration of formaldehyde(0, 1, 5mg/m3), trichloroethylene(0, 100, 5000mg/m3)and their mixture(1+1000mg/m3, 1+5000mg/m3, 5+1000mg/m3, 5+5000mg/m3) for 14 days, 2 hours per day, then kill them on the 15 th day. Through the determination of the mice spleen, thymus organ coefficient, the mice peripheral blood the content of CD3+ and the ratio of CD4+/CD8+, the DTH intensity, the level changes of the mice peripheral blood Ig M, Ig G, Ig E and IL-4, SOD, GSH-Px activity and MDA content of the mice spleen and thymus, we from immune pathology, cell immunity, humoral immunity and the oxidative damage of immune organs to comprehensive observe and analysis the toxic effects on the immune system of mice and the possible mechanism after exposed to formaldehyde and trichloroethylene alone or both. Results:1.The damage of immune system(1)Immune Pathology Index Exposed to gaseous formaldehyde can make the mice spleen and thymus coefficient decreasing obviously(P<0.05), exposing to gaseous trichloroethylene can make the mice thymus coefficient decreasing obviously(P<0.05), and with the toxicant exposure concentration increase showed a decreasing trend,compared with the control group.(2)The Cellular Immune Index①The Content of CD3+ and the Ratio of CD4+/CD8+ of the Peripheral Blood Exposed to gaseous formaldehyde can make the content of CD3+ of the mice peripheral blood decreasing obviously(P<0.05), the ratio of CD4+/CD8+ increasing obviously(P<0.05), and showed a dose effect relationship; exposed to gaseous trichloroethylene can make the content of CD3+ and the ratio of CD4+/CD8+ increasing obviously(P<0.05), and showed a dose effect relationship; there exist interaction among the content of CD3+ and the ratio of CD4+/CD8+ of the female mice peripheral blood(P<0.05), and the type of interaction maybe is antagonistic,compared with the control group.②The Delayed Hypersensitivity Intensity Exposed to gaseous formaldehyde and trichloroethylene separately can make the female mice DTH intensity decreasing obviously(P<0.05), and with the toxicant exposure concentration increase showed a decreasing trend. There exist interaction among female mice DTH intensity after exposed to the mixture of gaseous formaldehyde and trichloroethylene(P<0.05), the type pf interaction maybe is antagonistic, compared with the control group.(3)The Humoral Immune Index Exposed to gaseous formaldehyde can make the level of Ig M, Ig E, IL-4 increasing obviously(P<0.05), exposed to gaseous trichloroethylene can make the level of Ig E increasing obviously(P<0.05), and with the toxicant exposure concentration increase showed a decreasing trend; exposed to gaseous formaldehyde and trichloroethylene separately has no obvious influence on the level of Ig G(P>0.05); there still has no evidence to indicates the existence of interaction among the level of Ig M, Ig G, Ig E, IL-4(P>0.05), compared with the control group.2.The oxidative damage of mice spleen and thymus(1)The oxidative damage of the mice spleen Exposed to gaseous formaldehyde and trichloroethylene separately can make the activity of SOD and GSH-P x on the mice spleen decreasing obviously(P<0.05), the content of MDA increasing obviously(P<0.05), and with the toxicant exposure concentration increase showed a decreasing trend, compared with the control group. There exist interaction among the activity of SOD and the content of MDA on the female mice spleen, after exposed to formaldehyde and trichloroethylene; the type on the activity of SOD seems to be synergy, while the type on the content of MDA seems to be antagonistic.(2)The oxidative damage of the mice thymus Exposed to gaseous formaldehyde and trichloroethylene separately can make the activity of SOD and GSH-Px on the mice thymus decreasing obviously(P<0.05); the content of MDA increasing obviously(P<0.05), and with the toxicant exposure concentration increase showed a decreasing trend, compared with the control group. There exist interaction among the activity of SOD and the content of MDA on the thymus mice spleen, after exposed to formaldehyde and trichloroethylene; the type on the activity of SOD seems to be synergy, while the type on the content of MDA seems to be antagonistic. Conclusions:Formaldehyde and trichloroethylene are common indoor air pollutants. Both formaldehyde and trichloroethylene separated and joint exposing can damage the immune system of the mice. The results showed that formaldehyde and trichloroethylene both can cause the damage of mice immune pathology, cellular immunity and humoral immunity, and the damage effect may exist gender differences, the immunotoxicity seems to be more obviously on the female mice, the interaction function type may be is antagonism; there still has no evidence indicates the existence of obvious interaction on the male mice. Lipid peroxidation damage may be the main mechanisms of the immunotoxicity of formaldehyde and trichloroethylene. |
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