HPLC测定PVC输液袋中的邻苯二甲酸二(2-乙基己基)酯

目的 测定PVC输液袋中增塑剂邻苯二甲酸二(2-乙基己基)酯(DEHP)的含量.方法 采用HPLC法,流动相为甲醇-水(90:10),流速为1.0 ml·min-1,检测波长为222 nm.结果 峰面积与DEHP浓度的线性关系良好(r=0.9999).结论 所用方法简便,结果准确可靠.     

新生儿静脉营养液中邻苯二甲酸二(2-乙基)己酯含量检测

目的建立气相色谱-质谱联用(GC-MS)法测定新生儿静脉营养液中邻苯二甲酸二(2-乙基)己酯(DEHP)的含量。方法收集放置不同时间段的新生儿静脉营养液,采用GC-MS进行定性定量,考察其DEHP的含量及其变化。结果新生儿静脉营养液中DEHP量随软袋放置时间延长而增加,测得放置24 h DEHP为3.23 mg·L-1。结论新生儿静脉营养液中放置24 h,溶出的DEHP量低于新生儿耐受摄入量,但也对新生儿带来危害。     

活性氧在邻苯二甲酸单(2-乙基己基)酯所致心肌细胞DNA损伤中的作用

目的 探讨邻苯二甲酸单(2-乙基己基)酯(MEHP)对人源心肌AC16细胞DNA的损伤作用及其可能机制。方法 以人源心肌AC16细胞为研究对象,分为对照组,40、60、80、100和120μmol/L MEHP组。处理细胞24 h后采用DCFH-DA探针标记测定AC16细胞内活性氧(ROS)水平;单细胞凝胶电泳实验测定细胞DNA损伤情况;利用抗氧化剂N-乙酰-L-半胱氨酸(NAC)抑制AC16细胞内ROS生成,以观察ROS在MEHP所致AC16细胞DNA损伤中的作用。结果 与对照组相比,AC16细胞经MEHP处理后,ROS水平随着MEHP浓度的增加而明显升高(P<0.05);对照组心肌细胞核呈圆形荧光团,强度均匀,边缘光滑,大小较一致,无明显拖尾。不同浓度MEHP处理后,各组心肌细胞出现彗星拖尾现象,且具有MEHP浓度依赖性。与对照组OTM值和TD值相比,MEHP组OTM值和TD值明显升高,且有统计学意义(P<0.05);预先给予NAC可明显降低MEHP所致的细胞ROS水平升高。与相应的MEHP组相比,NAC+MEHP组OTM值及TD值明显降低,且差异有统计学意义(P<...     

蓝氧片对邻苯二甲酸(2-乙基己基)酯致小鼠睾丸超微形态结构损害的保护作用

目的 观察塑化剂邻苯二甲酸(2-乙基己基)酯(DEHP)对小鼠睾丸超微形态结构的影响,并研究蓝氧片(专利药用组合Y523)对小鼠睾丸生精细胞和支持细胞的保护和修复作用及其机制。方法 55只成年♂小鼠随机分为DEHP组、Y523组和对照组。DEHP组以大豆油为溶剂,剂量分别为：0,10,20,50,和100 mg·kg^-1·d^-1,连续30 d灌胃染毒;Y523组以等量大豆油混合1 000 mg蓝氧片原料粉剂连续30 d灌胃给药后重复DEHP组的灌胃染毒过程;对照组以标准饲料同期喂养。采用透射电镜观察小鼠睾丸超微结构的改变。结果 与对照组相比,随着DEHP灌胃染毒剂量的递增,DEHP组小鼠睾丸生精细胞出现胞膜塌陷,核质疏松,小细胞器消失,空泡形成,甚至整个生精细胞层消失;支持细胞胞膜皱缩,核质浓缩,胞质内空泡形成和凋亡小体样结构。与DEHP组相比,蓝氧片组小鼠睾丸生精细胞和支持细胞的超微形态结构改变与对应剂量DEHP灌胃染毒的DEHP组小鼠基本类似,但胞质内线粒体、溶酶体等小细胞器的数量明显增多。结论 DEHP灌胃染毒可致小鼠睾丸生精细胞空泡样变性退化,细胞胀亡和凋亡。蓝氧片对DEHP所致的睾丸损害有一定的保护作用,其机制可能与小鼠睾丸支持细胞内线粒体和溶酶体等细胞器数量的增加有关。     

邻苯二甲酸二-（2-乙基己基）酯对小鼠胚胎致畸作用和心肌细胞的毒性

邻苯二甲酸酯类被广泛用作增塑剂，在某些塑料产品中，含量甚至高达50％。由于其应用广泛，及易于从塑料中迁移出来，故对环境污染严重。而邻苯二甲酸二-(2-乙基己基)酯(DEHP)的用量占了增塑剂的25％，主要用于食品包装和医用器材等。动物实验表明邻苯二甲酸酯类具有致畸性，亦有资料表明它是内分泌干扰物。     

应用胚胎干细胞试验(EST)评价邻苯二甲酸二(2-乙基)己酯(DEHP)的胚胎毒性

目的利用小鼠胚胎干细胞试验(EST)模型,初步评价邻苯二甲酸二(2-乙基)己酯(DEHP)的胚胎毒性。方法采用悬滴悬浮法培养小鼠胚胎干细胞(m ESCs),观察受试物对m ESCs分化能力的影响,结合CCK-8法判断受试物对m ESCs及小鼠胚胎成纤维细胞(3T3)的细胞毒性结果,预测受试物的胚胎毒性。用已知强胚胎毒性化合物5-氟尿嘧啶(5-Fluorouracil,5-FU)、无胚胎毒性化合物青霉素-G(P-G)对模型进行有效性验证,并将经过验证的EST模型用于评价受试物DEHP的胚胎毒性。结果利用建立的EST模型对5-FU、P-G胚胎毒性进行评价,结果表明5-FU为强胚胎毒性,P-G为无胚胎毒性,与文献报道一致;DEHP对m ESCs和3T3的半数抑制浓度分别为IC50m ESCs=315μmol/L(126μg/ml),IC503T3=307μmol/L(122.8μg/ml),m ESCs的半数抑制分化浓度为ID50m ESCs=323μmol/L(129.2μg/ml),经EST模型判断公式计算得出该化合物为弱胚胎毒性化合物。结论建立的EST模型的有效性验证结果与ECVAM的结论一致,可用于胚胎毒性的筛选和评价;经EST模型评价DEHP的胚胎毒性为弱胚胎毒性。     

邻苯二甲酸二乙基己酯体内代谢和毒性机制研究进展

塑化剂被广泛用于各种塑料制品当中,其中以邻苯二甲酸二乙基己酯(DEHP)最为典型。随着食品中添加塑化剂的新闻不断被曝光,塑化剂对人体健康的危害逐渐引起大众关注。塑化剂及其体内代谢物在体内的蓄积可导致多个器官的损伤。塑化剂生殖器官蓄积可造成生殖系统明显的损伤,在肝脏累积可导致氧化应激而引发肝细胞凋亡,同时塑化剂又能作为佐剂影响免疫系统。该文将就DEHP的生殖毒性、肝脏毒性和免疫毒性及其有关机制进行了系统阐述。     

邻苯二甲酸二乙基己酯对成年大鼠睾丸前列腺素E2含量及COX-2 mRNA表达的影响

目的:研究邻苯二甲酸二乙基己酯(DE-HP)对成年大鼠睾丸前列腺素E2(PGE2)含量及环氧合酶-2(COX-2)mRNA表达的影响。方法:雄性SD成年大鼠40只,随机分成4组,每组10只,设3个染毒剂量组(10、100、500 mg.kg-1.d-1DEHP溶媒为玉米油)和1个对照组(玉米油),饲养4周后处死。用ELISA测定睾丸组织PGE2含量;应用免疫组化法检测40只雄性SD成年大鼠睾丸组织中COX-2的表达及其定位情况;RT-PCR法检测各组睾丸组织COX-2 mRNA表达及其定位情况。结果:实验组睾丸组织中PGE2含量和睾丸组织的COX-2mRNA表达均低于对照组,COX-2则主要表达于精原细胞。结论:DEHP能使成年大鼠睾丸生精细胞功能损伤,使睾丸组织PGE2合成降低,其机制可能与下调COX-2 mRNA表达有关。     

邻苯二甲酸二乙基己基酯对胎鼠肺发育的抑制作用

目的探讨孕大鼠染毒邻苯二甲酸二乙基己基酯(DEHP)对胎鼠肺发育的抑制作用及其可能机制。方法 Sprague-Dawley大鼠受孕后第12天每天ig给予DEHP0,10,100和750mg.kg-1,至自然分娩。第1天每窝随机取自然分娩仔鼠3只,测定体质量;光镜观察肺组织病理学改变及测定辐射状肺泡计数(RAC)和肺间质比例,免疫组化法检测基质金属蛋白酶-2(MMP-2)、基质金属蛋白酶组织抑制剂-2(TIMP-2)和血管内皮生长因子(VEGF)的表达。结果与正常对照组相比,DEHP组仔鼠体质量明显下降(P<0.01)。光镜下仅DEHP750mg.kg-1组可见肺间质增厚,间质细胞增多,肺泡数目减少,RAC减小,肺间质比例增大(P<0.05)。与正常对照组比较,DEHP组VEGF表达差异无统计学意义;DEHP10,100和750mg.kg-1组MMP-2表达和MMP-2/TIMP-2值明显高于正常对照组〔MMP-2分别为0.099±0.009,0.124±0.008,0.140±0.010vs0.091±0.011(P<0.01);MMP-2/TIMP-2分别为1.079±0.074,1.447±0.077,1.704±0.084vs0.994±0.079(P<0.01)〕。结论孕鼠染毒DEHP后对胚胎生长和肺发育有抑制作用。DEHP抑制胎鼠肺发育的机制可能与MMP-2的过度表达以及MMP-2/TIMP-2平衡失调有关。     

Toxicokinetic relationship between di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate in rats

The toxicokinetic relationship between di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate (MEHP), a major metabolite of DEHP, was investigated in Sprague-Dawley rats orally treated with a single dose of 14C-DEHP. Urinary excretion of total 14C-DEHP and of its metabolites was followed by liquid scintillation counting (LSC). Concentrations of DEHP and MEHP were determined 6, 24, and 48 h after treatment in rat serum and 6, 12, 24, and 48 h after treatment in urine by high-performance liquid chromatography (HPLC). After 24 h, peak concentrations of MEHP in both urine and serum were observed in animals treated with 40, 200, or 1000 mg DEHP/kg. HPLC showed that general toxicokinetic parameters, such as Tmax (h), Cmax (microg/ml), Ke (1/h), and AUC (microg-h/ml/) were greater for MEHP than DEHP in both urine and serum. In contrast, the half-lives (t1/2 [h]) of DEHP were greater than those of MEHP. The AUC ratios between DEHP and MEHP were relatively smaller in serum than in urine, suggesting the important role of urinary DEHP data for exposure assessment of DEHP. The toxicokinetic relationship between DEHP and MEHP in rats suggests that DEHP exposure assessment should be based on DEHP and MEHP in urine and serum for risk assessment applications.     

No background concentrations of di(2-ethylhexyl) phthalate and mono(2-ethylhexyl) phthalate in blood of rats

We measured the background levels of di(2-ethylhexyl) phthalate (DEHP) and its hydrolytic metabolite mono(2-ethylhexyl) phthalate (MEHP) in blood from naive female Sprague-Dawley rats and in de-ionized charcoal-purified water using an analytical procedure that is based on sample treatment with acetonitrile, n-hexane extraction and analysis by gas chromatography. In blood, blank values of 91.3 +/- 34.7 micrograms DEHP/l (n = 31) and 30.1 +/- 13.1 micrograms MEHP/l (n = 20) were obtained, and in water, values of 91.6 +/- 44.2 micrograms DEHP/l (n = 26) and 26.7 +/- 10.4 micrograms MEHP/l (n = 15) were found. Since there is no difference between the background valves obtained from blood of naive rats and water, we conclude that DEHP and MEHP result from contamination during the analytical procedure.     

Chronic toxicity of di(2-ethylhexyl)phthalate in rats.

Fischer 344 rats were treated with 0, 100, 500, 2500, or 12,500 ppm di(2-ethylhexyl)phthalate (DEHP) in the diet for up to 104 weeks. Blood and urine were analyzed at weeks 26, 52, 78, and 104 from 10 animals per sex per group. Survival was slightly but not statistically reduced for rats receiving 12,500 ppm DEHP. Body weights and food consumption were significantly reduced for rats receiving the highest dose level of DEHP and occasionally for the male 2500-ppm group. BUN and albumin were significantly higher and globulin lower at nearly every sampling interval for the 12,500-ppm group compared with the controls. There was an increase in the mean activities of AST and ALT at 104 weeks, but no statistically significant differences were seen. Erythrocyte count, hemoglobin, and hematocrit values for the 12,500-ppm group were significantly lower than controls at nearly every sampling interval. No other differences in hematology were seen. No toxicologically significant changes were observed in urinalysis. At termination, relative lung weights for the 2500- and 12,500-ppm male groups of rats were significantly higher than for the controls. Absolute and relative liver and kidney weights for the 2500- and 12,500-ppm male rats, and liver weights for 12,500-ppm female rats were higher compared with the controls. Absolute and relative testes weights for the 12, 500-ppm male rats were lower compared with the controls. All organs were examined for histopathology. The incidence of hepatocellular lesions has been reported separately and correlated with the induction of peroxisomal enzyme activity (David et al., 1999). A dose level of 500 ppm was the NOEL for peroxisome proliferation. Bilateral aspermatogenesis in the testes, castration cells in the pituitary gland, spongiosis hepatis, and pancreatic acinar cell adenoma were observed for 12,500-ppm male rats. Aspermatogenesis and spongiosis hepatis were observed for 2500-ppm male rats, and aspermatogenesis was seen at 500 ppm. DEHP exposure exacerbated age-, species- or strain-related lesions such as mineralization of the renal papilla and chronic progressive nephropathy in male rats. Kupffer cell pigmentation and renal tubule pigmentation were seen in male and female 12,500-ppm rats. The increased incidence of spongiosis hepatis correlated with increased palmitoyl CoA oxidase activity, but the incidence of pancreatic acinar cell adenoma was increased only at the highest dose level of 12,500 ppm. These lesions, although typical of those seen with other peroxisome proliferators, may respond differently depending on the potency of the peroxisome proliferator. A dose level of 500 ppm (28.9-36.1 mg/kg/day) was considered to be the NOAEL.     

Comparison of the short-term effects of di(2-ethylhexyl) phthalate, di(n-hexyl) phthalate, and di(n-octyl) phthalate in rats

This study compares changes in the livers of rats treated with di(2-ethylhexyl) phthalate (DEHP) and its straight-chain analogs di(n-hexyl) phthalate (DnHP) and di(n-octyl phthalate (DnOP). Groups of rats were fed diets containing 20,000 ppm of one of these compounds. Subgroups were killed after 3, 10, and 21 days, and the livers were examined by histological, cytological, and biochemical methods. The results show considerable differences between the effects of the branched-chain phthalate ester DEHP and its straight-chain analogs. The major effects on the liver following administration of diets containing DEHP were midzonal and periportal accumulation of small droplets of lipid, hepatomegaly accompanied by an initial burst of mitosis, proliferation of hepatic peroxisomes and of smooth endoplasmic reticulum accompanied by induction of peroxisomal fatty acid oxidation, damage to the peroxisomal membranes as evidenced by increased leakage of catalase to the cytosol, and centrilobular loss of glycogen and falls in glucose-6-phosphatase activity and in low-molecular-weight reducing agents. In contrast, diets containing DnHP or DnOP induced accumulation of large droplets of fat around central veins leading, by 10 days, to mild centrilobular necrosis and a very slight induction of one peroxisomal enzyme and an increase in liver weight, but no significant changes in any other parameters which were affected by DEHP.     

Hepatic peroxisome proliferation and hypolipidemic effects of di(2-ethylhexyl)phthalate in neonatal and adult rats

To determine the relative sensitivity of suckling rats as compared to adults to the effects of di(2-ethylhexyl) phthalate (DEHP), five daily oral doses of 0, 10, 100, 1000, or 2000 mg DEHP/kg body weight were given to male Sprague-Dawley rats beginning at 6, 14, 16, 21, 42, and 86 days of age. Twenty-four hours after the last dose, rats were sacrificed and plasma cholesterol and triglyceride levels and the activities of the hepatic peroxisomal enzymes, palmitoyl CoA oxidase and carnitine acetyltransferase, were determined. Suckling rats (1-3 weeks of age) suffered severe growth retardation at doses of 1000 mg/kg and death at 2000 mg/kg while older rats only showed decreased weight gain at 2000 mg/kg. Of particular interest was the lethality at doses of 1000 mg/kg at 14 days of age but not at 16 days or at other ages. Increases in relative liver weight and hepatic peroxisomal enzyme activities were similar in all age groups except the 14-day old group in which the increases were greater. Relative kidney weight was increased in 21-, 42-, and 86-day-old rats at the highest doses but not in younger rats. Hypolipidemia was observed only in 21-, 42-, and 86-day-old rats at doses of 1000 and 2000 mg/kg, while elevated plasma cholesterol levels were observed in 6- and 14-day-old rats at the 1000 mg/kg dose, possibly due to the dietary differences between suckling and weaned rats. The results suggest that neonatal and suckling rats are more sensitive to the lethal and growth retardation effects of DEHP than are adult rats, but the hepatic peroxisome proliferation is similar at all ages with the exception of a greater increase at 14 days of age.     

Induction of propranolol metabolism in isolated rats hepatocytes treated by di(2-ethylhexyl) phthalate (DEHP) and mono(2-ethylhexyl) phthalate (MEHP).

Blood lines of polyvinyl chloride (PVC) for hemodialysis usually contain di(2-ethylhexyl) phthalate (DEHP) as a plasticizer. Previous studies show that 1 mg/kg of this plasticizer can leach into the blood during one dialysis session. It is rapidly metabolized in the liver. Mono(2-ehtylhexyl) phthalate (MEHP), its main metabolite can be detected as well. After oral administration to rodents, both compounds caused a variety of adverse biological effects such as testicular atrophy, peroxisome proliferation and hepatic peroxisomal enzyme induction. Male wistar rats were treated intraperitoneally by DEHP and MEHP using twice the dose of that involved in human exposure during a dialysis session. Propranolol metabolism by hepatocytes was investigated after fresh isolation from treated and untreated rats by means of reverse phase HPLC. The choice of propranolol as a substrate was made because of its rather quick liver metabolisation. Phenobarbital was chosen in the study as a reference of enzymatic inducer to evaluate the inducing effect of DEHP and MEHP. Propranolol was metabolized by the hepatocytes of both treated and untreated rats. Hepatocytes isolated from rats treated by phenobarbital, MEHP and DEHP were shown to have a higher speed constant of metabolism indicating a rapid metabolism of propranolol. Under these conditions, in fact, propranolol metabolisation was found to be respectively 6, 2.7, 2 times faster than the propranolol metabolisation of untreated rats. The hypothesis that DEHP and MEHP are enzymatic inducers, particularly cytochrome P450 (CYP) inducers of the xenobiotics metabolism on the intact liver after IP administration has become been found to be valid. The results obtained in this study confirm the value of isolated hepatocytes as an in vivo drug metabolism predictive model.     

Assessment of the teratogenicity of di(2-ethylhexyl)phthalate and mono(2-ethylhexyl)phthalate in mice

Di(2-ethylhexyl)phthalate (DEHP) and mono(2-ethylhexyl)phthalate (MEHP) were administered PO or IP to pregnant ICR mice at varying doses on days 7, 8, and 9 of gestation. In groups given DEHP orally, resorptions and malformed fetuses increased significantly at 1,000 mg/kg. Fetal weights were also significantly suppressed. Anterior neural tube defects (anencephaly and exencephaly) were the malformations most commonly produced. No teratogenic effects were revealed by IP doses of DEHP and PO or IP doses of MEHP, although high doses were abortifacient and lethal to pregnant females. Thus DEHP is highly embryotoxic and teratogenic in mice when given PO but not IP. The difference in metabolism, disposition, or excretion by the route of administration may be responsible for the difference in DEHP teratogenicity. Although MEHP is a principal metabolite of DEHP and is several times more toxic than DEHP to adult mice, it seems that MEHP and its metabolites are not teratogenic in ICR mice.     

Antiandrogenic effects in male rats perinatally exposed to a mixture of di(2-ethylhexyl) phthalate and di(2-ethylhexyl) adipate

Di(2-ethylhexyl) phthalate (DEHP) is a well-known testicular toxicant inducing adverse effects in androgen responsive tissues. Therefore, di(2-ethylhexyl) adipate (DEHA) is currently being evaluated as a potential substitute for DEHP. Similarities in structure and metabolism of DEHP and DEHA have led to the hypothesis that DEHA can modulate the effects of DEHP. Wistar rats were gavaged with either vehicle, DEHP (300 or 750 mg/kg bw/day) or DEHP (750 mg/kg bw/day) in combination with DEHA (400 mg/kg bw/day) from gestation day (GD) 7 to postnatal day (PND) 17.

Decreased anogenital distance (AGD) and retention of nipples in male offspring were found in all three exposed groups. Dosed males exhibited decreased weights of ventral prostate and m. levator ani/bulbocavernosus. Histopathological investigations revealed alterations in testis morphology in both juvenile and adult animals. The litter size was decreased and postnatal mortality was increased in the combination group only, which is likely a combined effect of DEHP and DEHA. However, no combination effect was seen with respect to antiandrogenic effects, as males receiving DEHP in combination with DEHA did not exhibit more pronounced effects in the reproductive system than males receiving DEHP alone.     

Effect of di(2-ethylhexyl)phthalate (DEHP) on spermatogenesis in adult rats

Oral administration of di(2-ethylhexyl)phthalate (DEHP) in doses of 250, 500, 1000 and 2000 mg/kg to adult rats for 15 days caused a significant dose dependent decrease in the sperm count of the epididymal spermatozoa. The activity of gamma-glutamyl transpeptidase (gamma GT) and lactate dehydrogenase (LDH) was significantly increased in the animals of the treated groups. An increase in the activity of beta-glucuronidase and decrease in the activity of acid phosphatase was also observed at the highest dose of DEHP. The activity of sorbitol dehydrogenase (SDH) was found to be decreased in the animals exposed to 1000 and 2000 mg/kg of DEHP. These results suggest that DEHP can affect spermatogenesis by altering the activities of the enzymes responsible for the maturation of sperms. The reduced number of sperms may be responsible for the antifertilic effects of DEHP.