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Background trichlorethylene (Trichloroethylene, TCE) is a common industrial organic halogenated hydrocarbon solvent, it is fat-soluble substances volatile, colorless, nonflammable liquid, chloroform-like odor, can be used as metal go greasing agent, dry cleaners, solvent extraction, etc., each year 5-6 million tons of TCE usage, widely used in hardware, electronics, toys, printing and other industries. Cause damage to the body past its role mainly in the kidney, central and peripheral nervous system, heart, reproductive system and other organ damage. In recent years, research has found that it can also cause serious skin damage, many scholars believe that the skin damage caused by the TCE belongs Ⅳ type delayed type hypersensitivity mediated by T lymphocytes, clinical, however, only the T lymphocyte-mediated type Ⅳ the delayed hypersensitivity not yet fully explain the mechanism of skin damage. Also found that in recent years many cause of deaths and serious liver damage caused by multiple organ failure, liver damage caused by TCE sensitized people, according to TCE drug eruption-like dermatitis cases The investigation found TCE drug eruption-like dermatitis patients often associated with severe liver injury, liver injury is caused by multiple organ failure leading cause of death. Workplace exposure caused by exogenous compounds skin inflammatory disorders collectively referred to as the occupational contact dermatitis (Occupational contact dermatitis, OCD), depending on the pathogenesis of contact dermatitis is usually divided into irritant contact dermatitis (Irritant contact dermatitis ICD) and allergic contact dermatitis (Allergic contact dermatitis, ACD), due to the only T lymphocyte mediated delayed hypersensitivity type Ⅳ it may still not be completely explained TCE mechanism of skin damage caused by, show that TCE The drug rash-like skin lesions may not only T-lymphocyte-mediated type Ⅳ delayed hypersensitivity. Objective To study the TCE guinea pig skin sensitization and its mechanism of action, by detecting the guinea pig liver function indicators research TCE sensitized to cause damage to the liver. Possible mechanism by detecting oxidative stress indicators, explore TCE sensitized guinea pig liver injury. 3 Methods weighing 250-300g / white female guinea pigs after adaptability feeding a week, and randomly divided into blank control group, solvent control group (olive oil) of TCE group and DNCB positive control group. With an electric razor to remove back hair, about 4cm-6cm take a complete skin damage was animal 24 hours after randomization for the test. Guinea pigs back from the beginning to the tail the L1; R1; L2; R2; L3; R3 of 3 to 6 points, each point spacing 1.5cm spacing 3cm. L1, R1 two injection 0.1ml Freund's complete adjuvant (FCA); L2, R2 two injections 0.1ml test substance; L3, and a mixture of test substance equivalent the R3 two injections 0.1mlFCA with. 1d with 5% TCE (TCE: olive oil = 5:95) and 0.25% DNCB (DNCB: acetone: olive oil = 1:3:397) intradermal injection of the initial sensitization, the control group was injected with L1; R1 two FCA, L2, R2 two undiluted excipients, and L3, R3, two points with a 1:1 (V / V) FCA / water or saline formulated in a concentration of 50% (w / v), of the shaped agent. At the injection site 7d smear 10% sodium dodecyl sulfate, in 8d 40% TCE coated leather and 0.50% DNCB painted skin sensitization with saline wash after 48 hours in the first 15d with 20% TCE painted skin and 0.25% DNCB painted skin excited 24 hours after cleaning with saline. Based on the toxicity of chemicals identified technical specifications \Table 2.1 skin reaction score. When the test sample group of animal skin reaction score ≥ 1, should be sentenced for skin sensitization reaction positive tested samples sensitized strength grading according to Table 2.2. After the recovery of the guinea pig blood, antiserum kit malondialdehyde (Malondialdehyde, MDA), superoxide dismutase (Superoxide dismutase, SOD) content and activity. Determination of liver function indicators, including indicators of ALT, AST, ALB, SPSS10.0 statistical package for statistical analysis of the experimental results in the automatic biochemical analyzer. 4 results in skin sensitization test, the control group and the olive oil control group showed no erythema or edema DNCB positive control group of seven animals were erythema and edema response, sensitization rate was 100%; TCE test 9 erythema group of 14 animals, sensitization rate was 64.29%. 2 in guinea pig liver, liver function tests found that sensitized guinea pig liver ALT and AST indicators blank and olive oil control group differences were significant; in same batch excitation guinea pigs, sensitized positive group, ALT, AST The indicators are significantly higher than the group of guinea pigs sensitized negative inspection differences significant; DNCB positive control group of guinea pig liver ALT and AST indicators tested and found positive control group and the control group, as well as olive oil compared to the control group , ALT, AST indicators no significant differences. 3, after the detection of the guinea pig serum lipid peroxide levels found sensitized guinea pig serum MDA levels compared to the control group was decreased significantly statistical tests differences; same batch stimulate the guinea pig sensitized positive group and negative group guinea pigs sensitized MDA levels compared sensitized positive guinea pig MDA decreased significantly; guinea pig serum SOD level detection sensitized positive guinea pig and compared to the control group showed an increasing trend, The statistical test differences significant; TCE sensitized positive group and SOD levels of TCE sensitized negative guinea pigs, positive group SOD levels were significantly increased. 5 Conclusion 1 TCE dose guinea pig sensitization are strong allergens. After TCE sensitized guinea pig liver damage rather than just damage to the skin, and this damage is related to the role of TCE. TCE result in sensitized guinea pigs in vivo lipid peroxidation level change, increased activity of the antioxidant enzymes SOD and MDA levels decreased. The mechanism of injury may cause liver damage due to lipid peroxidation and needs further study, but the specific mechanism of damage caused by free radicals.
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