三氯乙烯及其代谢产物的豚鼠皮肤致敏作用研究

目的研究三氯乙烯(TCE)及其代谢产物三氯乙酸(TCA)、三氯乙醇(TCOH)对豚鼠皮肤致敏作用。方法选用体重250~300 g SPF级白化Hartley豚鼠,雌雄各半,按OECD豚鼠最大值实验法,用TCE、TCOH、TCA分别对豚鼠进行皮内注射和涂皮结合法致敏,并设空白对照组及阳性对照组(二硝基氯苯,DNCB),观察各组动物皮肤的红斑和水肿等情况,计算致敏率。在终末激发24 h后用乙醚麻醉动物后处死,取涂抹部位及邻近皮肤进行病理学检查。结果 TCE、TCOH、TCA致敏率分别为80%、35%、0%,TCE致敏阳性组豚鼠皮肤可见中度弥漫的红斑、轻度水肿;TCOH致敏阳性组豚鼠皮肤可见散在或小块红斑。病理检查显示TCE致敏阳性组豚鼠表皮棘细胞层明显增厚,真皮乳头层及网织层可见淋巴细胞、嗜酸性粒细胞弥散或聚集性浸润及毛细血管轻度充血;TCOH致敏阳性组豚鼠表皮棘细胞层轻度增厚,真皮乳头层及网织层嗜酸性粒细胞弥散或聚集性浸润,夹杂少量淋巴细胞。结论TCE、TCOE可使豚鼠皮肤发生过敏性改变,TCE是强致敏物,TCOH为中度致敏物,TCA未见致敏作用。     

豚鼠最大值试验法研究二氯乙酰氯皮肤致敏作用的初步报告

目的探讨二氯乙酰氯(DCAC)是否在三氯乙烯药疹样皮炎发病过程中起到半抗原的作用。方法按豚鼠最大值试验(GPMT)法,用DCAC对白色豚鼠进行皮内和涂皮结合法致敏试验,并设阳性对照组(二硝基氯苯)、阴性对照组(橄榄油和福氏完全佐剂),观察各组动物皮肤的红斑和水肿等情况,求出致敏率和平均反应值,并且检测ALT和AST以及计算各脏器系数。结果 DCAC实验组、阳性对照组和阴性对照组的致敏率分别为0%、100%和0%;平均反应值分别为0、6.0和0;各实验组豚鼠的ALT和AST以及脏器系数差异无统计学意义。结论 DCAC可能在三氯乙烯药疹样皮炎发病过程中没有起到半抗原的作用,并且对实验动物没有明显肝功能损害。     

三氯乙烯致豚鼠皮肤变态反应和血清免疫球蛋白水平改变

目的:探讨三氯乙烯(TCE)对豚鼠皮肤变态反应和血清免疫球蛋白水平的改变。方法:采用豚鼠最大值试验GPMT,动物分成阴性对照组、阳性对照组和TCE实验组,每组6只豚鼠,分别皮内注射橄榄油、2,4-二硝基氯苯(DNCB)和TCE。实验结束后观察动物皮肤改变,应用自动生化分析仪检测致敏动物血清免疫球蛋白水平。结果:阳性对照组和TCE实验组动物出现明显皮肤损害,阳性对照组动物致敏率为100%,TCE实验组致敏率为83.3%。TCE致敏豚鼠血清总IgG含量明显高于阴性对照组(P0.05)。结论:三氯乙烯属于强致敏物,可诱导豚鼠产生皮肤变态反应,引起血清免疫球蛋白改变。     

三氯乙烯对豚鼠皮肤致敏作用与肝肾功能的损害

目的 探讨三氯乙烯(TCE)对豚鼠皮肤致敏作用及肝肾功能的损害.方法 采用豚鼠最大值试验(GPMT),将动物分成阴性对照组、阳性对照组和TCE实验组,每组6只豚鼠,分别皮内注射橄榄油、2,4-二硝基氯苯(DNCB)和TCE.实验结束后观察动物皮肤改变,应用自动生化分析仪检测致敏动物血清中丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)、白蛋白、球蛋白、乳酸脱氧酶(LDH)、肌苷、尿酸等指标.结果阳性对照组和TCE实验组动物出现明显皮肤红斑、水肿,阳性对照组动物致敏率为100%,TCE实验组动物致敏率为83.3%.阳性对照组动物血清中ALT、AST活力升高,TCE实验组动物血清中ALT、AST、LDH活力明显高于阴性对照组,差异有统计学意义(P＜0.05或P＜0.01).结论 TCE可诱导豚鼠产生明显的皮肤致敏作用,属强致敏物,并可引起实验动物肝功能指标的改变.     

三氯乙烯致敏豚鼠及IL-10表达的研究

目的研究细胞因子白细胞介素-10(IL-10)在三氯乙烯(TCE)致敏豚鼠表皮中的表达,探讨TCE药疹样皮炎发病机制。方法将白色雌性豚鼠随机分成空白对照组、溶剂对照组、TCE实验组、2,4—二硝基氯苯(DNCB)阳性对照组,根据豚鼠最大反应试验(guinea pig maximization test,GPMT)方法处理豚鼠,在终末激发后进行皮肤反应评分,皮肤反应评分≥1判断为致敏,依据致敏结果以及取材时间的不同将TCE实验组分为致敏组24 h、72 h和未致敏组24 h、72 h,DNCB阳性对照组24 h和72 h。无菌条件下取皮制成蜡块,采用Elivison二步法免疫组织化学法检测各组表皮中IL-10的表达情况。结果 TCE实验组致敏率为62.1%;TCE致敏24 h组和72 h组的IL-10水平高于溶剂对照组,且差异有统计学意义(P0.05);同时TCE致敏24 h组与TCE未致敏24 h组比较、TCE致敏72 h组与TCE未致敏72 h组比较,差异也有统计学意义(P0.05);TCE致敏24 h组与DNCB 24 h组比较,差异有统计学意义(P0.05)。结论 TCE对豚鼠皮肤具有致敏作用,IL-10在TCE药疹样皮炎发生过程中具有重要意义。     

应用BrdU-ELISA法检测化学物皮肤致敏性研究

目的研究应用BrdU-ELISA法检测化学物皮肤致敏性。方法将受试物2，4-二硝基氯苯（DNCB）、三氯乙烯（TCE）、三氯乙酸、抗菌冻胶对小鼠双耳背皮肤进行涂抹，25μl／耳，连续染毒3d，第4天每只小鼠腹腔注射BrdU标记液（0．3ml／只）。第5天取小鼠耳部淋巴结称重，然后制成单细胞悬液，应用BrdU-ELISA法检测淋巴细胞增殖。同时应用豚鼠局部封闭涂皮法检测受试物的致敏性。结果DNCB、TCE各浓度组与AOO溶剂对照组BrdU标记值比较，差异均存在统计学意义（P〈0．01），DNCB各浓度组与AOO溶剂对照组淋巴结重量比较，差异均存在统计学意义（P〈0．01），而TCE各浓度组与AOO溶剂对照组淋巴结重量比较，差异无统计学意义（P〉0．05）。抗菌凝胶组与三氯乙酸分别与空白对照组比较，其中抗菌凝胶组、1％、5％三氯乙酸BrdU标记值差异均无统计学意义，10％三氯乙酸差异则存在统计学意义（P〈0．05）。结论BrdU-ELISA法具有检测化学物皮肤致敏性的能力，但其灵敏性比标准LLNA和传统豚鼠局部封闭涂皮法差，需要进一步优化实验方法。     

三氯乙烯致敏豚鼠血清中肿瘤坏死因子-α和白细胞介素-1β水平的变化

目的 比较三氯乙烯(TCE)致敏豚鼠和未致敏豚鼠血清中白细胞介素(IL)-1β和肿瘤坏死因子(TNF)-α水平.方法 将豚鼠随机分为空白对照组,溶剂(橄榄油)对照组,2,4-二硝基氯苯(DNCB)阳性对照组,TCE处理组.根据豚鼠最大值试验(Guinea pig maximization test,GPMT)方法处理豚鼠.按照<化学品毒性鉴定技术规范>的评分标准对动物的皮肤反应进行评分,评分≥1的判为致敏.在末次激发后24 h和72 h分2批采血,用聚合酶链反应试剂盒测定血清中TNF-α、和IL-1β的含量.结果 DNCB组致敏率为100%,TCE组致敏率为62.1%.DNCB阳性对照组和TCE致敏组TNF-α和IL-1β水平与溶剂对照组相比明显升高(P<0.05).在24 h及72 h 2个时点,TCE致敏动物TNF-α和IL-1β水平比相应的未致敏组高,差异有显著性(P<0.05).结论 在TCE诱导的致敏豚鼠血清中TNF-α和IL-1β水平升高.     

三氯乙烯致敏豚鼠皮肤组织中白细胞介素-1、-6和-8表达的研究

目的研究白细胞介素(IL)-1、IL-6和IL-8在三氯乙烯(TCE)致敏豚鼠皮肤组织中的表达情况,探讨TCE药疹样皮炎发病机制。方法将白色雌性豚鼠随机分成空白对照组、溶剂对照组、TCE实验组、2,4-二硝基氯苯(DNCB)阳性对照组,根据豚鼠最大值试验(GPMT)方法处理豚鼠,在终末激发后(依据致敏结果以及取材时点的不同,将TCE实验组以及DNCB阳性对照组分为TCE致敏组24 h、TCE致敏组72 h、TCE未致敏组24 h和TCE未致敏组72 h;DNCB组24 h和DNCB组72 h)进行皮肤反应评分,并采取皮肤组织,制成蜡块,采用Elivison二步法免疫组织化学法检测各组皮肤组织中IL-1、IL-6和IL-8的表达情况。结果根据皮肤反应评分≥1判断为致敏阳性,TCE实验组致敏率为62.1%;TCE致敏组24 h和TCE致敏组72 h的IL-1水平要显著高于溶剂对照组,且差异有统计学意义(P<0.05);同时TCE致敏组24 h与TCE未致敏组24 h比较、TCE致敏组72 h与TCE未致敏组72 h比较差异也有统计学意义(P<0.05),但IL-6和IL-8水平在各个组别和不同时间点之间差异无统计...     

83—1除草剂对豚鼠皮肤致敏作用的实验研究

作者采用豚鼠耐受试验对83—1除草剂进行皮肤致敏性检测,结果显示,实际喷洒浓度(0.16%)及最大溶解浓度(0.35%)对豚鼠致敏率均为0%,受试皮肤未发现致敏征象及组织病理改变,细胞免疫功能(Ea、Et试验)也未见增强,可以认为83—1除草剂无致敏作用,推论到人是安全的。     

重组人乳铁蛋白皮肤变态反应和皮肤光变态反应试验研究

目的确定和评价重组表达的人乳铁蛋白作为化妆品原料对哺乳动物引起变态反应或者光变态反应的程度。方法通过豚鼠皮肤变态反应试验和弗氏完全佐剂试验法考察重组人乳铁蛋白的致敏性和光敏性。结果皮肤变态反应试验中,受试物重组人乳铁蛋白未见引起皮肤红斑、水肿等过敏症状反应,且未见其他中毒指标(受试物组中皮肤反应积分≥2的动物数为0例,致敏率为0%);皮肤光变态反应试验中,豚鼠皮肤局部涂抹受试物重组人乳铁蛋白后进行UVA照射,未引起皮肤刺激和过敏等光变态反应(受试物组中皮肤反应积分≥2的动物数为0例,致敏率为0%)。结论重组人乳铁蛋白无皮肤致敏性和光致敏性。     

Trichloroethylene metabolism in chronic liver disorders induced by carbon tetrachloride

Numerous reports have been published in the field of industrial health on biological monitoring of trichloroethylene exposure, but these studies have been confined to healthy humans. Trichloroethylene metabolism in individuals with chronic liver diseases has not been clarified. This experiment was therefore performed on rats that were administrated carbon tetrachloride subcutaneously for three months to induce chronic liver damage. The metabolism of trichloroethylene and its metabolites, chloral hydrate and trichloroethanol, were investigated using the isolated liver perfusion method. Comparing the changes of these substances in the chronically damaged liver with those in the intact liver, the following results were observed in the chronically damaged liver: The conversion of trichloroethylene to trichloroethanol and trichloroacetic acid decreased. The reduction of chloral hydrate to trichloroethanol increased. The oxidation of chloral hydrate to trichloroacetic acid decreased. The biliary excretion of trichloroethanol and trichloroacetic acid decreased.     

Measurement of chloral hydrate,trichloroethanol, trichloroacetic acid and monochloroacetic acid in the serum and the urine by gas chromatography

Summary A gas chromatographic method for the determination of trichloroethylene metabolites in the serum and the urine is described.The trichloroethanol glucuronide in the urine was hydrolyzed to trichloroethanol by -glucuronidase. After an extraction with ethyl ether, the extract was dried at 20C, then the residue was extracted with n-hexane and was injected into a gas Chromatograph.Trichloroacetic acid and monochloroacetic acid in the urine were extracted with ethyl ether. After evaporation of the ethyl ether, the acids were methylated with methanolic hydrogen chloride, by heating, and the residue was taken up in n-hexane and was injected into a gas chromatograph. The peak-areas on the gas chromatogram of the trichloroethylene, chloral hydrate and methyl esters of trichloroacetic acid and monochloroacetic acid were measured respectively, using a calibration curve prepared in the same conditions.Procedure for measuring trichloro-compounds in the serum was the same as for that in the urine, except that the ethyl ether extraction of trichloro-compounds was conducted after deproteinization.The serum concentration of trichloro-compounds in the rabbit, after administering trichloroethylene orally, reached the maximum in the following order: trichloroethylene and chloral hydrate > free trichloroethanol, trichloroethanol glucuronide and monochloroacetic acid > trichloroacetic acid. The urinary metabolites of trichloroethylene did so in the following order: free trichloroethanol and monochloroacetic acid > trichloroethanol glucuronide > trichloroacetic acid.Read before the 45th Annual Meeting of Japan Industrial Health Association, Tokyo, April 8, 1972.     

Metabolism and Excretion of Trichloroethylene after Inhalation by Human Subjects

Eight volunteers were exposed to trichloroethylene vapour (1,042 μg./l.) for five hours; 51 to 64% of the inhaled trichloroethylene was retained. The concentration of trichloroethanol and trichloroacetic acid in the urine was studied daily for a three-week period; on the third day both metabolites were determined in faeces, sweat, and saliva. The concentration of trichloroacetic acid in plasma and red blood cells was studied on alternate days. Of the trichloroethylene retained, 38·0 to 49·7% was excreted in the urine as trichloroethanol and 27·4 to 35·7% as trichloroacetic acid. Of both metabolites 8·4% was excreted in the faeces. Sweat collected on the third day of the experiment contained 0·10 to 1·92 mg./100 ml. trichloroethanol and 0·15 to 0·35 mg./100 ml. trichloroacetic acid. In saliva the concentrations were 0·09 to 0·32 mg./100 ml. trichloroethanol and 0·10 to 0·15 mg./100 ml. trichloroacetic acid. The value of the expression trichloroethanol/trichloroacetic acid calculated in the urine within 22 days was within the range 1·15 to 1·81.     

Excretion of organic chlorine compounds in the urine of persons exposed to vapours of trichloroethylene and tetrachloroethylene

Ogata, M., Yoshiko, T., and Tomokuni, K. (1971).Brit. J. industr. Med.,28, 386-391. Excretion of organic chlorine compounds in the urine of persons exposed to vapours of trichloroethylene and tetrachloroethylene. Male volunteers were exposed to 170 p.p.m. of trichloroethylene vapour either for 3 hours or for 7 hours with one break of 1 hour; or to 87 p.p.m. of tetrachloroethylene vapour for 3 hours. Urine was collected frequently up to 100 hours after the start of exposure, and was analysed for trichloroethanol and trichloroacetic acid. After trichloroethylene exposure, trichloroethanol was excreted most rapidly shortly after exposure ceased, and trichloroacetic acid most rapidly 42 to 69 hours after exposure ceased. Total recoveries of trichloroethylene inhaled, up to 100 hours, were: trichloroethanol, after 3 hours' exposure, 53·1%; after 7 hours' exposure, 44%; trichloroacetic acid, similarly: 21·9% and 18·1%. The effects of exposure on blood pressure, pulse rate, flicker value, and reaction time were measured. The diastolic blood pressure was decreased significantly after 3 hours' exposure to 170 p.p.m. trichloroethylene. After tetrachloroethylene exposure, in 67 hours trichloroacetic acid was excreted to 1·8% tetrachloroethylene retained and an unknown chloride equivalent to 1·0%.

Urine samples from 10 workers in an automobile parts factory were analysed for trichloroethanol and trichloroacetic acid. Trichloroethanol concentrations in the urine taken after work were higher than in the urine taken before work while for trichloroacetic acid the concentrations were reversed, due to the difference in the time course of excretion. The urinary levels of trichloroethanol, trichloroacetic acid, and total trichloro compounds were almost proportional to the environmental concentration of trichloroethylene.

     

Effect of Tetraethyl Thiuram Disulphide (Disulfiram) on Metabolism of Trichloroethylene in Man

The amounts of trichloroethanol and trichloroacetic acid excreted in the urine of four subjects who inhaled trichloroethylene in a concentration of about 1 mg./l. for a period of five hours in a laboratory experiment were determined. This experiment was repeated under the same conditions after tetraethyl thiuram disulphide (disulfiram) had been given in divided doses, totalling 3 or 3·5 g. The elimination of trichloroethanol in urine was decreased by 40 to 64%, and of trichloroacetic acid by 72 to 87%. The trichloroethylene excreted by the lungs in two of the subjects increased up to 65% of that retained within five hours. It is concluded that tetraethyl thiuram disulphide (disulfiram) strikingly inhibits the oxidation of trichloroethylene.

The possible therapeutic use of this substance in cases of severe peroral trichloroethylene intoxication is discussed.

     

A simple method for the quantitative analysis of urinary trichloroethanol and trichloroacetic acid as an index of trichloroethylene exposure

Ogata, M., Takatsuka, Y., and Tomokuni, K. (1970).Brit. J. industr. Med.,27, 378-381. A simple method for the quantitative analysis of urinary trichloroethanol and trichloroacetic acid as an index of trichloroethylene exposure. A simple method of estimating trichloroethanol and trichloroacetic acid in the urine of workers exposed to trichloroethylene is described. The glucuronide of trichloroethanol was hydrolysed enzymatically to trichloroethanol by β-glucuronidase and the trichloroethanol released was allowed to react with pyridine and potassium hydroxide in that order, thereby avoiding decomposition of trichloroethanol with strong alkali. The colour which developed in 3·5 minutes at 100°C with pyridine was measured at 440 nm and 530 nm. This also allowed trichloroacetic acid to be determined. The results agreed well with those obtained by longer methods.     

Mutagenicity of trichloroethylene and its metabolites: implications for the risk assessment of trichloroethylene

This article addresses the evidence that trichloroethylene (TCE) or its metabolites might mediate tumor formation via a mutagenic mode of action. We review and draw conclusions from the published mutagenicity and genotoxicity information for TCE and its metabolites, chloral hydrate (CH), dichloroacetic acid (DCA), trichloroacetic acid (TCA), trichloroethanol, S-(1, 2-dichlorovinyl)-l-cysteine (DCVC), and S-(1, 2-dichlorovinyl) glutathione (DCVG). The new U.S. Environmental Protection Agency proposed Cancer Risk Assessment Guidelines provide for an assessment of the key events involved in the development of specific tumors. Consistent with this thinking, we provide a new and general strategy for interpreting genotoxicity data that goes beyond a simple determination that the chemical is or is not genotoxic. For TCE, we conclude that the weight of the evidence argues that chemically induced mutation is unlikely to be a key event in the induction of human tumors that might be caused by TCE itself (as the parent compound) and its metabolites, CH, DCA, and TCA. This conclusion derives primarily from the fact that these chemicals require very high doses to be genotoxic. There is not enough information to draw any conclusions for trichloroethanol and the two trichloroethylene conjugates, DCVC and DCVG. There is some evidence that DCVC is a more potent mutagen than CH, DCA, or TCA. Unfortunately, definitive conclusions as to whether TCE will induce tumors in humans via a mutagenic mode of action cannot be drawn from the available information. More research, including the development and use of new techniques, is required before it is possible to make a definitive assessment as to whether chemically induced mutation is a key event in any human tumors resulting from exposure to TCE.     

An experimental examination of extra-hepatic metabolism of trichloroethylene in dogs

To investigate the extra-hepatic organs metabolism of trichloroethylene, the extra-hepatic circulation in dogs was established by operating on the portal vein-right femoral vein bypass and other locations. These dogs were exposed for one hour to trichloroethylene at concentrations of 700 ppm. Metabolite (trichloroethanol (F-TCE), trichloroacetic acid (TCA) and total trichloroethanol (T-TCE) changes in serum and urine were measured from the beginning of exposure until one hour after termination, and compared with previous data as control. The following results were obtained. This operation method gave a very slight invasion on dogs. About two hours after the operation, no abnormal findings were observed clinically or physiologically. This method was considered to be one of the best for study of the metabolism of chemical substances in the extra-hepatic organs of dogs. The produced ratios of F-TCE, TCA and T-TCE in extrahepatic organs were about 60, 10 and 30% exposure to trichloroethylene at 700 ppm, respectively.     

Assessment of Urban Population Exposure to Trichloroethylene and Tetrachloroethylene by Means of Biological Monitoring

Exposure of the general population to trichloroethylene and tetrachloroethylene under normal environmental conditions, achieved with biological monitoring, was assessed, and the possible influence of these compounds via drinking water on the body burden was revealed. A total of 79 subjects with no known solvent exposure was selected, by stratified sampling, from the residents of the city of Zagreb. Trichloroethylene and tetrachloroethylene were determined in blood, and trichloroethanol and trichloroacetic acid were determined in plasma and urine. Drinking water samples were also analyzed for trichloroethylene and tetrachloroethylene. Concentrations of trichloroethylene and tetrachloroethylene in blood, trichloroacetic acid in plasma, trichloroacetic acid in urine, trichloroethylene in drinking water, and tetrachloroethylene in drinking water were as follows: < 0.015 to 0.090 μg/l, < 0.010 to 0.239 μg/l, 8.6 to 148.1 μg/l, 1.67 to 102.3 μg/24 h, < 0.05 to 22.93 μg/l, and 0.21 to 7.80 μg/l, respectively. The variation in all results presented is probably a reflection of different environmental contamination with trichloroethylene and tetrachloroethylene in the different city areas. Correlation analyses revealed significant relationships between trichloroethylene and tetrachloroethylene in blood (r = .402, p = .0004); trichloroacetic acid in urine and in plasma (r = .522, p = .0000); and trichloroethylene and tetrachloroethylene in drinking water (r = .800, p = .0000). A division of all parameters into a subgroup (n = 58), taking drinking water concentrations of trichloroethylene above 3 μg/l as a basis, demonstrated the same significant relationships as mentioned above. Significant correlations, however, appeared between both In trichloroethylene and In tetrachloroethylene in drinking water, compared with In trichloroacetic acid in plasma and urine, which could be a result of the influence of contaminated drinking water on body burden.     

Assessment of intermittent trichloroethylene exposure in vapor degreasing.

To validate various sampling strategies in assessment of trichloroethylene (TCE) exposure, urine and air samples were obtained from 29 metal workers involved in vapor degreasing. Urinary trichloroacetic acid and trichloroethanol were useful metabolites to estimate TCE exposure on a group basis, but the predictive value of a single urine sample was low when related to the air concentration. With intermittent TCE exposure, the best information is obtained by analyzing both metabolites.