甲基叔下基醚对大鼠肝组织基因表达的影响

目的 甲基叔丁基醚（ＭＴＢＥ）是一种新型的汽油添加剂,动物试验显示其具有一定的致癌性。为了了解其动物致癌性的可能机制,我们检测了经ＭＴＢＥ亚慢性染毒的大直组织中原癌基因ｃ－ｍｙｃ基因和功能基因谷胱甘肽Ｓ－转移酶Ｐ（ＧＳＴ－Ｐ）基因的表达情况。方法 ４０例雄性ＳＤ大鼠,体重１８０－２００ｇ,随机分为４组。将ＭＴＢＥ溶于适量豆油中,灌胃染毒,染毒剂量分别为２００ｍｇ／ｋｇ,６００ｍｇ／ｋｇ,１０００ｍ     

甲基叔丁基醚对原癌基因和功能基因表达的影响

甲基叔丁基醚（ＭＴＢＥ）是一种新型的汽油添加剂,被用来提高汽油燃烧效率,减少汽车尾气中有害物质的排放。ＭＴＢＥ具有一定的动物致癌性,但其机制目前并不清楚。本研究采用免疫组织化学方法,检测了ＭＴＢＥ对体外培养的ＮＩＨ３Ｔ３细胞中ｃ－ｍｙｃ和ｐ２１蛋白表达的影响;采用点杂交方法,从ＲＮＡ水平检测了ＭＴＢＥ亚慢性染毒大鼠肝组织中原癌基因ｃ－ｍｙｃ基因和功能基因ＧＳＴ－Ｐ基因的表达情况。免疫组化结果显示,ＭＴＢＥ可诱导ｃ－ｍｙｃ基因的高表达,对ｐ２１蛋白的表达未见明显影响。点杂交结果显示,ＭＴＢＥ可明显诱导大鼠肝组织中ｃ－ｍｙｃ基因的高表达,而对ＧＳＴ－Ｐ基因的表达未见明显影响。上述结果提示,ＭＴＢＥ可诱导细胞中ｃ－ｍｙｃ基因表达活性增高,可能是其动物致癌性的机制之一。     

弓形虫P30基因在大肠杆菌中的表达研究

将编码弓形虫主要表面膜抗原（Ｐ３０）基因插入原核表达载体ｐＧＥＭＥＸ１的Ｔ７启动子下游,构建的重组质粒ｐＧＥＭＥＸ１／Ｐ３０转入宿主菌Ｅ．ｃｏｌｉＢＬ２１（ＤＥ３）。用ＩＰＴＧ诱导Ｐ３０基因表达,ＳＤＳＰＡＧＥ和Ｗｅｓｔｅｒｎｂｌｏｔ实验表明重组子能够表达３０ｋＤ蛋白,表达产物可以和兔抗弓形虫阳性血清特异性结合,具有较好的免疫原性。     

苯并（a）芘对小鼠腹腔巨噬细胞功能影响的研究

以２０、１０、５ｍｇ／ｋｇ Ｂ（ａ）ｐ连续灌胃１０天染毒小鼠，观察Ｂ（ａ）ｐ对小鼠腹腔巨噬细胞（ＰＥＣ）吞噬功能及Ｆｃ受体功能的影响。结果表明，总剂量为２００ｍｇ／ｋｇ的Ｂ（ａ）ｐ染毒组，小鼠ＰＥＣ吞噬率为２５．９％，对照组为４３．９％，吞噬率下降近５０％；剂量为１００、５０ｍｇ／ｋｇ的Ｂ（ａ）ｐ染毒组，未见ＰＥＣ吞噬率有明显变化。在三个染毒剂量组，均未见小鼠ＰＥＣ Ｆｃ受体功能有明显的变化。     

甲基叔丁基醚的急性毒性研究

为研究国产甲基叔丁基醚（ＭＴＢＥ）的毒性,比较与国外产品的异同,选用大、小鼠及家兔,采用经口、呼吸道及皮肤等染毒途径,同时对国产及进口ＭＴＢＥ的急性毒性进行研究,结果表明：国产及进口ＭＴＢＥ的小鼠经口ＬＤ５０分别为２９４５．２和２９４４．４ｍｇ／ｋｇ,大鼠均为３４３３．６ｍｇ／ｋｇ。小鼠经呼吸道ＬＣ５０分别为７２９８８．３和９９６３０ｍｇ／ｍ３,大鼠为８５３２０和１０３４１０ｍｇ／ｍ３。急性中毒表现均为先兴奋,然后出现粘膜刺激症状,运动失调,活动减少,麻醉,最后死亡。兔经皮染毒仅见脱脂现象,无致炎、致敏或中毒作用。但对兔眼睛有较强致炎作用。结论：国产或进口ＭＴＢＥ的动物经口或经呼吸道急性毒性基本相同,均属低毒物,经皮属微毒物,但对兔眼有明显刺激和致炎作用     

甲基汞诱发大鼠肾脏脂质过氧化作用的探讨

采用ＴＢＡ及ＤＴＮＢ比色法，测定不同染毒时间和染毒剂量，甲基汞对大鼠肾脏丙二醛（ＭＤＡ）含量及谷胱甘肽过氧化物酶（ＧＳＨ—ＰＸ）活性的影响。结果发现染毒组ＭＤＡ含量均显著高于对照组（Ｐ＜０．０２～Ｐ＜０．０１），染毒后２４ｈ处死动物，除５．０ｍｇ／ｋｇ·ｗｔ组ＭＤＡ含量显著低于对照组外（Ｐ＜０．００１），其余各剂量组ＭＤＡ含量均分别高于各自的对照组（Ｐ＜０．０１～Ｐ＜０．０５）。另外，雌性大鼠肾脏ＧＳＨ－Ｐｘ活性于染毒后２４ｈ、７２ｈ显著低于对照组（Ｐ＜０．００１，Ｐ＜０．０１）。     

EGE与甲苯和二甲苯联合处理对大鼠EGE代谢和睾丸的影响

男油漆工接触乙二醇乙醚（ＥＧＥ）可引起睾丸萎缩。本研究观察了ＥＧＥ与甲苯和二甲苯联合处理对大鼠睾丸萎缩和血浆中乙氧基乙酸（ＥＡＡ）生成的影响。选用雄性大鼠,体重２５０～３００ｇ。为观察不同剂量ＥＧＥ单独以及与甲苯和二甲苯联合处理对大鼠睾丸的影响,每日经口单独给大鼠ＥＧＥ橄榄油溶液５０、１００、２００、５００和１０００ｍｇ／ｋｇ;同时与甲苯２５０ｍｇ／ｋｇ、二甲苯５００ｍｇ／ｋｇ及甲苯５００ｍｇ／ｋｇ和二甲苯１０００ｍｇ／ｋｇ共同处理;对照组经口给橄榄油０８ｍｌ,每周６次共４周,在最后一次染毒后…     

乙醇对雄性生殖内分泌系统的损害及其机制

目的研究乙醇对雄性生殖内分泌系统损害机制。方法测定饮酒和酒精中毒者血Ｔ、ＬＨ、ＦＳＨ、Ｅ２、ＬＤＨ、ＬＤＨ－Ｘ、Ｇ－６ＰＤ水平和乙醇染毒大鼠血和睾丸匀浆Ｔ、ＬＨ、ＦＳＨ、ＭＤＡ、ＳＯＤ、ＧＳＨ－ＰＸ、ＣＡＴ、－ＳＨ水平。结果３０００、４０００ｍｇ／ｋｇ染毒７０天大鼠血Ｔ明显下降,ＬＨ、Ｅ２、ＦＳＨ升高,血和睾丸匀浆ＭＤＡ明显升高,而ＳＯＤ、ＧＳＨ－ＰＸ－ＳＨ明显下降,饮酒和酒精中毒者血Ｔ明显下降,     

用细胞转移法研究苯并（a）芘损伤机理

ＢＡＬＡ／Ｃ雌性小鼠一次腹腔注射２００ｍｇ／ｋｇ体重的苯并（ａ）芘（Ｂ（ａ）ｐ）．体液免疫功能受到明显的抑制，脾ＩｇＭ—ＰＦＣ和ＩｇＧ－ＰＦＣ抑制率分别为４４％和６４％．如果给Ｂ（ａ）ｐ染毒小鼠输入正常小鼠的Ｔ细胞或Ｂ细胞，可使受Ｂ（ａ）ｐ抑制的小鼠免疫功能恢复到接近对照组的水平．说明Ｂ（ａ）Ｐ可同时作用于Ｔ细胞和Ｂ细胞．     

镉对免疫系统的影响及与前列腺素的关系

应用心得安和前列腺素动物模型观察了镉对免疫系统的影响及与前列腺素Ｅ２（ＰＧＥ２）的关系。结果表明：整体动物实验时，ＰＧＥ２和淋巴细胞ｃＡＭＰ在镉单独作用各组均有升高趋势。淋巴细胞ｃＡＭＰ在心得安单独作用时，５ｍｇ／ｋｇ组低于对照组（Ｐ＜０．０５）；１５ｍｇ／ｋｇ组高于对照组（Ｐ＜０．０５）。还见心得安高剂量组的ＰＧＥ２显著低于镉中剂量组和消炎痛＋镉组（Ｐ均＜０．０５）。体外培养人外周血淋巴细胞时见镉组及消炎痛＋镉组的ＡＣ酶活性和ｃＡＭＰ含量均显著升高；心得安＋镉组的ＡＣ酶活性与对照组比较无显著性差异，ｃＡＭＰ含量在两作用组中有一组无显著变化。此外，消炎痛可阻断巨噬细胞分泌ＰＣＥ２，且能缓解镉对巨噬细胞的抑制。结果提示：心得安的作用较消炎痛明显，即在镉的免疫毒性作用机制中，β肾上素能受体机制存在的可能性大于ＰＧＥｃＡＭＰ机制。     

Red wine and black tea polyphenols modulate the expression of cycloxygenase-2, inducible nitric oxide synthase and glutathione-related enzymes in azoxymethane-induced f344 rat colon tumors

Polyphenolic compounds extracted from red wine (WE) and black tea (BT), 50 mg/(kg. d), inhibit the promotion phase of the colon carcinogenesis process induced by azoxymethane (AOM) in rodents. To investigate possible mechanisms of this protective activity, we evaluated by RT-PCR the gene expression of cycloxygenase-2 (COX-2), inducible NO synthase (iNOS), gamma-glutamylcysteine synthetase (gamma-GCS) and two isoforms of glutathione S-transferase (GST), GST-P and GST-M2, in 30 AOM-induced tumors and in the corresponding normal colon mucosa. AOM-induced colon tumors had significantly greater GST-P, GST-M2, COX-2 and iNOS gene expression than the corresponding normal mucosa. However, tumors harvested from rats treated with BT (P < 0.05) and WE (P < 0.01) polyphenols had a lower GST-P mRNA level than tumors from controls. Treatment with WE polyphenols induced a similar inhibitory effect on the colon tumor overexpression of GST-M2 (P < 0.01), COX-2 (P < 0.05) and iNOS (P < 0.05). In the normal mucosa, rats treated with BT polyphenols had greater gamma-GCS expression than controls (P < 0.01). Our results provide evidence that WE and BT polyphenols modulate COX-2, iNOS and glutathione-related gene expression in tumors, suggesting that these compounds have possible chemotherapeutic activity.     

三氯乙烯染毒SD大鼠肝脏的基因表达图谱

目的分析三氯乙烯(TCE)染毒多次后SD大鼠肝脏的基因表达图谱,为研究机体多次接触TCE其肝脏所产生的分子毒理学反应特性提供线索。方法SD大鼠背部皮内注射体积分数为15%的TCE,每7d1次。分别于第5和第7次染毒后24h收集大鼠的肝脏组织,提取总RNA,用Affymetrix的大鼠U34毒理基因芯片分析其基因表达谱。结果大鼠染毒TCE5次及7次24h肝脏中的Gadd45a、Myc和Mel基因及与固醇类、脂类代谢合成相关的基因或电子传递相关的P450家族基因显著性上调表达,而部分P450家族和热胁迫基因则下调表达。结论本文首次报道了SD大鼠多次接触TCE后肝脏组织的基因表达图谱。     

镉对大鼠肝细胞原癌基因c-myc表达的影响

应用Ｎｏｒｔｈｅｒｎ斑点杂交方法研究氯化镉对大鼠肝细胞原癌基因ｃ－ｍｙｃ表达的影响。结果表明,５ｕｍｏｌ／ｋｇ、１０ｕｍｏｌ／ｋｇ、２０ｕｍｏｌ／ｋｇ氯化镉腹腔一次注射邱,大鼠肝细胞ｃ－ｍｙｃｍＲＮＡ较对照组明显增多,用免疫组化技术在大鼠肝细胞中检测到ｃ－ｍｙｃ蛋白。结果提示,氯化镉可以引起在体大鼠肝细胞ｃ－ｍｙｃ表达增强。     

Inhibitory effects of dietary caraway essential oils on 1,2-dimethylhydrazine-induced colon carcinogenesis is mediated by liver xenobiotic metabolizing enzymes

The effects of dietary essential oils prepared from caraway seeds on colon carcinogenesis induced by 1,2-dimethylhydrazine (DMH) in rats has been studied. The number of aberrant crypt foci (ACF) and aberrant crypt (AC) induced by DMH were found to be significantly inhibited in colon of rats treated with essential oils in diet (0.01 and 0.1%). To find out the mechanism(s) by which the essential oils reduced colon premalignancies, plasma, liver, and colon tissues were collected and analyzed for parameters related to oxidative stress and xenobiotic metabolizing enzymes. Lack of influence of caraway extracts on hepatic lipid peroxidation products, superoxide dismutase (SOD), catalase (CAT) and ferric reducing ability of plasma (FRAP) may suggest that the oils do not interfere with these factors. However, it was clearly shown that DMH-related changes in hepatic and colonic cytochrome P4501A1 (CYP1A1) and glutathione S-transferae (GST) activities were recovered in liver but not in colon tissue in animals treated with caraway oil preparations. In conclusion, histopathological and biochemical data clearly showed that inhibition of colon premalignant lesions induced by DMH is mediated by interference of caraway oil components in the activities of the main hepatic xenobiotic metabolizing enzymes.     

Dietary fish protein alters blood lipid concentrations and hepatic genes involved in cholesterol homeostasis in the rat model

It is known that various dietary plant proteins are capable of influencing the lipid metabolism of human subjects and animals when compared with casein. Less, however, is known about the effects of fish protein on the cholesterol and triacylglycerol metabolism. Therefore, two experiments were conducted in which rats were fed diets containing 200 g of either fish protein, prepared from Alaska pollack fillets, or casein, which served as control, per kilogram, over 20 and 22 d, respectively. As parameters of lipid metabolism, the concentrations of cholesterol and triacylglycerols in the plasma and liver, the faecal excretion of bile acids and the hepatic expression of genes encoding proteins involved in lipid homeostasis were determined. In both experiments, rats fed fish protein had higher concentrations of cholesteryl esters in the liver, a lower concentration of cholesterol in the HDL fraction (rho > 1.063 kg/l) and lower plasma triacylglycerol concentrations than rats fed casein (P < 0.05). The gene expression analysis performed in experiment 2 showed that rats fed fish protein had higher relative mRNA concentrations of sterol regulatory element-binding protein (SREBP)-2, 3-hydroxy-3-methylglutaryl coenzyme A reductase, LDL receptor, apo AI, scavenger receptor B1 and lecithin-cholesterol-acyltransferase in their liver than did rats fed casein (P < 0.05). The faecal excretion of bile acids and the mRNA concentrations of cholesterol 7alpha-hydroxylase, SREBP-1c and corresponding target genes were not altered. These findings show that fish protein had multiple effects on plasma and liver lipids that were at least in part caused by an altered expression of the hepatic genes involved in lipid homeostasis.     

茶色素防癌作用的实验研究

作者用一组体外短期检测试验,检验了茶色素在肿瘤的起动、促进、增殖阶段的作用并与茶多酚进行比较。选用基因正向突变和周期阻断法微核实验作为起动阶段指标,选用代谢协作和小鼠耳炎性水肿实验作为促癌阶段指标,选用Ｈｅｌａ 细胞存活率和软琼脂生长及小鼠Ｓ１８０实体瘤实验,检测对肿瘤细胞存活和增殖的影响。结果发现茶色素与茶多酚在肿瘤发生的起动、促进和增殖各阶段均显示出明显的保护作用;体外给予茶多酚、茶色素处理Ｈｅｐ Ｇ２肝肿瘤细胞,发现茶色素及其单体成分及茶多酚可诱导醌还原酶（ＱＲ）活性和谷胱甘肽硫转移酶（ＧＳＴ）活性;在用二乙基亚硝胺（ＤＥＮ）诱导的大鼠肝癌前病变,阳性对照组的ＧＳＴ水平有一定程度的降低;饮用０．１％ 茶多酚、茶色素可显著诱导大鼠肝ＧＳＴ活性,茶多酚的诱导率为２５％ ,茶色素的诱导率为１８％ ,而且ＧＳＴ１－１、１－２、３－３蛋白表达均有明显升高。结果表明茶色素与茶多酚同样具有抗肿瘤作用,茶色素对具有抗氧化作用和解毒作用的Ⅱ相代谢酶ＱＲ和ＧＳＴ 具有诱导作用,这可能是茶色素防癌作用的重要机制     

云锡矿工肺癌N-ras、c-myc和c-fos原位杂交检测

目的探讨云锡矿工肺癌发病机制。方法用原位分子杂交的方法，检测２０例云锡矿工肺癌（Ｍ组）、２０例其它地区非矿工肺癌（ＮＭ组）以及１０例死于非肺部疾患者的尸解肺组织（Ｃ组）中Ｎ－ｒａｓ、ｃ－ｍｙｃ及ｃ－ｆｏｓ癌基因的过表达情况。结果癌基因过表达出现率：Ｍ组Ｎ－ｒａｓ５５％（１１／２０）、ｃ－ｍｙｃ５０％（１０／２０）、ｃ－ｆｏｓ２５％（５／２０）；ＮＭ组Ｎ－ｒａｓ８０％（１６／２０）、ｃ－ｍｙｃ５５％（１１／２０）、ｃ－ｆｏｓ６０％（１２／２０）；Ｃ组３个癌基因过表达率均仅为１０％（１／１０）。表明Ｎ－ｒａｓ、ｃ－ｍｙｃ的过表达与肺癌的发生有关；ｃ－ｆｏｓ与矿工肺癌发生的关系不明显而与非矿工肺癌的发生有关。有２种或３种癌基因同时表达的，Ｍ组分别为４５％、２０％；ＮＭ组分别为７５％、２５％。癌旁增生上皮中发现有阳性反应。结论肺癌的发生可能与２种或２种以上癌基因过表达有关。矿工与其他人群肺癌的发生机制可能有不同之处。     

Gene expression analysis of the pro-oestrous-stage rat uterus reveals neuroligin 2 as a novel steroid-regulated gene

In the present study, differential gene expression in the uteri of ovariectomised (OVX) and pro-oestrous rats (OVX v. pro-oestrus pair) was investigated using cDNA expression array analysis. Differential uterine gene expression in OVX rats and progesterone (P(4))-injected OVX rats (OVX v. OVX + P(4) pair) was also examined. The uterine gene expression profiles of these two sets of animals were also compared for the effects of P(4) treatment. RNA samples were extracted from uterine tissues and reverse transcribed in the presence of [alpha(32)P]-dATP. Membrane sets of rat arrays were hybridised with cDNA probe sets. Northern blot analysis was used to validate the relative gene expression patterns obtained from the cDNA array. Of the 1176 cDNAs examined, 23 genes showed significant (>two-fold) changes in expression in the OVX v. pro-oestrus pair. Twenty of these genes were upregulated during pro-oestrus compared with their expression in the OVX rat uterus. In the OVX v. OVX + P(4) pair, 22 genes showed significant (>two-fold) changes in gene expression. Twenty of these genes were upregulated in the OVX + P(4) animals. The genes for nuclear factor I-XI, afadin, neuroligin 2, semaphorin Z, calpain 4, cyclase-associated protein homologue, thymosin beta-4X and p8 were significantly upregulated in the uteri of the pro-oestrus and OVX + P(4) rats of both experimental pairs compared with the OVX rat uteri. These genes appear to be under the control of P(4). One of the most interesting findings of the present study is the unexpected and marked expression of the neuroligin 2 gene in the rat uterus. This gene is expressed at high levels in the central nervous system and acts as a nerve cell adhesion factor. According to Northern blot analysis, neuroligin 2 gene expression was higher during the pro-oestrus and metoestrus stages than during the oestrus and dioestrus stages of the oestrous cycle. In addition, neuroligin 2 mRNA levels were increased by both 17beta-oestradiol (E(2)) and P(4), although P(4) administration upregulated gene expression to a greater extent than injection of E(2). These results indicate that neuroligin 2 gene expression in the rat uterus is under the control of both E(2) and P(4), which are secreted periodically during the oestrous cycle.