汽油尾氣致氧化應(yīng)激作用的實(shí)驗(yàn)研究
發(fā)布時(shí)間：2018-10-13 08:11
【摘要】： 汽油尾氣已成為許多城市室外空氣污染的主要來(lái)源，且其成分中含有許多已確證或可疑的人類致癌物，因此，進(jìn)一步明確汽油尾氣暴露與人體健康的關(guān)系就變得十分重要�，F(xiàn)的有研究資料顯示，汽油尾氣暴露與許多肺及肺外疾病的發(fā)生相關(guān)。雖然，1989年國(guó)際癌癥研究中心(IARC)將汽油尾氣歸為2B類人類致癌物，但迄今為止，對(duì)于人們最為關(guān)注的汽油尾氣暴露與肺癌的發(fā)生的關(guān)系，不論流行病學(xué)、動(dòng)物實(shí)驗(yàn)還是毒性機(jī)制研究方面的資料，都無(wú)法確認(rèn)和達(dá)成共識(shí)。為了了解汽油尾氣的毒作用機(jī)制及氧化損傷在其毒性機(jī)制中的作用，進(jìn)一步揭示汽油尾氣暴露與癌癥發(fā)生之間的關(guān)系，從而為汽油尾氣暴露與癌癥發(fā)生之間的關(guān)系提供實(shí)驗(yàn)依據(jù)。本研究以汽油尾氣的冷凝物、顆粒物和半揮發(fā)性有機(jī)物(Semivolatile organic compound，SVOC)三相成分的有機(jī)提取物為處理因素，探討了汽油尾氣對(duì)體外培養(yǎng)細(xì)胞和氣管滴注染毒后的動(dòng)物多器官組織細(xì)胞的氧化損傷作用。 體外試驗(yàn)中以人肺腺癌上皮細(xì)胞株A549細(xì)胞為研究對(duì)象，通過(guò)MTT試驗(yàn)，2′，7′-二氯雙氫熒光素雙乙酸酯(DCFH-DA)活性氧測(cè)定實(shí)驗(yàn)、抗氧化試驗(yàn)、微核試驗(yàn)以及彗星試驗(yàn)對(duì)汽油尾氣影響細(xì)胞存活率、活性氧生成和脂類的氧化損傷、抗氧化酶活力以及造成細(xì)胞DNA的鏈斷裂和染色體損傷的情況進(jìn)行了觀察。結(jié)果顯示，汽油尾氣能降低細(xì)胞存活率，誘導(dǎo)細(xì)胞內(nèi)活性氧的生成和堆積，造成脂質(zhì)的氧化損傷和抗氧化酶活力降低，并能導(dǎo)致DNA單鏈斷裂的增加和染色體的損傷，表明汽油尾氣具有明顯的細(xì)胞毒性和遺傳毒性，而氧化應(yīng)激則可能是其毒作用機(jī)制之一。此外，通過(guò)還原性谷胱甘肽(Glutathion，GSH)對(duì)汽油尾氣毒效應(yīng)的干預(yù)實(shí)驗(yàn)表明GSH可以降低汽油尾氣的毒性效應(yīng)。表現(xiàn)為GSH預(yù)處理組的細(xì)胞存活率、活性氧含量和脂質(zhì)過(guò)氧化程度、抗氧化酶活力的下降以及DNA單鏈的斷裂情況明顯低于未干預(yù)組。該結(jié)果從另一個(gè)側(cè)面進(jìn)一步提示氧化損傷在汽油尾氣的毒效應(yīng)過(guò)程中具有重要的作用。 體內(nèi)實(shí)驗(yàn)依據(jù)美國(guó)環(huán)保局(EPA)關(guān)于新燃料毒性評(píng)價(jià)的規(guī)定，將汽油尾氣的三相有機(jī)提取物通過(guò)氣管滴注對(duì)SD大鼠進(jìn)行染毒，然后對(duì)肺臟、腦、肝臟和睪丸等器官進(jìn)行多指標(biāo)的實(shí)驗(yàn)觀察。結(jié)果表明，汽油尾氣可造成大鼠肺組織中脂類、蛋白質(zhì)和核酸的氧化損傷以及抗氧化酶活力的下降，此外病理組織切片觀察到肺組織的炎性損傷明顯加重。通過(guò)免疫組化觀察肺組織中DNA氧化損傷的關(guān)鍵性修復(fù)酶——8-羥基鳥(niǎo)嘌呤DNA糖苷酶-1(OGG1)含量的變化，結(jié)果顯示汽油尾氣的暴露可導(dǎo)致肺組織8-羥基鳥(niǎo)嘌呤DNA糖苷酶-1的含量明顯增加：電鏡觀察肺組織細(xì)胞器細(xì)微結(jié)構(gòu)的變化，發(fā)現(xiàn)肺組織各型細(xì)胞中的線粒體損傷明顯，板層小體結(jié)構(gòu)發(fā)生病理改變，并有部分細(xì)胞核固縮。同樣，汽油尾氣暴露導(dǎo)致腦、肝臟和睪丸等器官組織中的脂質(zhì)過(guò)氧化產(chǎn)物丙二醛(MDA)和蛋白質(zhì)氧化損傷產(chǎn)物羰基蛋白(CP)的含量增加、抗氧化酶超氧化物歧化酶(SOD)和谷胱甘肽過(guò)氧化物酶(GPx)的活力下降(腦組織除外)、組織細(xì)胞DNA的鏈斷裂增加。動(dòng)物實(shí)驗(yàn)的結(jié)果表明，汽油尾氣經(jīng)呼吸道暴露后，肺是其主要的靶器官，但腦、肝、睪丸等其他臟器也會(huì)被累及，表明汽油尾氣暴露后的損傷是多器官的，而氧化應(yīng)激可能是其重要的毒作用機(jī)制之一。 體外體內(nèi)實(shí)驗(yàn)的結(jié)果均表明，，汽油尾氣暴露后可導(dǎo)致多組織多器官的脂類、核酸和蛋白質(zhì)等生物大分子的的氧化損傷，并能導(dǎo)致DNA損傷修復(fù)酶OGG1的量發(fā)生改變，這些損傷和變化也為癌癥的發(fā)生創(chuàng)造了可能。
[Abstract]:Gasoline tail gas has become the main source of outdoor air pollution in many cities, and its components contain many confirmed or suspected human carcinogens, so it becomes very important to further clarify the relationship between gasoline tail gas exposure and human health. The present study shows that the exposure of gasoline tail gas is related to the occurrence of many lung and extrapulmonary diseases. Although the 1989 International Cancer Research Centre (IARC) classifies gasoline off-gas as a 2B human carcinogen, Neither was able to confirm and reach consensus. In order to understand the toxic action mechanism of gasoline tail gas and the role of oxidative damage in its toxic mechanism, the relationship between the exposure of gasoline tail gas and the occurrence of cancer is further revealed, and the experimental basis is provided for the relationship between the exposure of gasoline tail gas and the occurrence of cancer. The effects of gasoline tail gas on the oxidative damage of multi-organ tissue cells in vitro cultured cells and trachea were investigated by using organic extracts of condensate, particulate matter and semi-volatile organic compound (SVOC) of gasoline tail gas as processing factors. In vitro test, human lung adenocarcinoma epithelial cell line A549 cell was used as the research object, and the tail gas shadow of gasoline was determined by MTT assay, 2-day, 7-day-dichloro-bishydrogen fluorescein diacetate (DCFH-DA) active oxygen measurement experiment, antioxidant test, micronucleus test and comet assay. In response to cell survival, the oxidative damage of active oxygen species and lipids, the activity of antioxidant enzymes, The results show that the tail gas of gasoline can reduce the cell survival rate, induce the generation and accumulation of active oxygen species in the cells, cause the oxidative damage of lipid and decrease the activity of antioxidant enzymes, and can lead to the increase of DNA single-strand breaks. The damage of the chromosome shows that the tail gas of gasoline has obvious cytotoxicity and genotoxicity, and oxidative stress may be its poison. In addition, the effect of reducing glutathione (GSH) on the tail gas toxicity of gasoline indicates that GSH can lower the tail of gasoline The results showed that the cell survival rate, reactive oxygen content and lipid peroxidation, the decrease of antioxidant enzyme activity and the fragmentation of DNA single strand in GSH pretreatment group were observed. lower than the non-intervention group. The result further suggests that oxidative damage occurs in the poison effect of gasoline tail gas from the other side In vivo, the three-phase organic extracts of gasoline tail gas were exposed to SD rats by air-gas instillation, and then lung, brain, liver and testis were treated according to EPA's regulations on new fuel toxicity evaluation. The results showed that the oxidative damage of lipid, protein and nucleic acid in lung tissue of rats and the decrease of antioxidant enzyme activity could be caused by the tail gas of gasoline, and the pathological tissue sections were observed. The results show that the exposure of gasoline tail gas can lead to 8-hydroxyproline DN in lung tissues. The changes of cell organelle structure of lung tissue were observed by electron microscope, and the damage of mitochondria in various cells of lung tissue was found to be obvious. In the same vein, the exposure of gasoline tail gas leads to lipid peroxidation products (MDA) and protein oxidative damage products in organs such as brain, liver and testis. The content of zinc finger protein (CP) increased, the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) decreased (except brain tissue). The results of animal experiments indicate that the lung is its main target organ after exposure to respiratory tract, but other organs, such as brain, liver and testis, can also be involved, indicating that the injury after exposure of gasoline tail gas is multi-organ, and oxidative stress can The results of in vitro experiments show that the oxidative damage of biological macromolecules such as lipids, nucleic acids and proteins of multiple organs can be caused after exposure of gasoline tail gas, and can resulting in a change in the amount of DNA damage repair enzyme OGG1
【學(xué)位授予單位】：四川大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2007
【分類號(hào)】：R363
本文編號(hào)：2267894
[Abstract]:Gasoline tail gas has become the main source of outdoor air pollution in many cities, and its components contain many confirmed or suspected human carcinogens, so it becomes very important to further clarify the relationship between gasoline tail gas exposure and human health. The present study shows that the exposure of gasoline tail gas is related to the occurrence of many lung and extrapulmonary diseases. Although the 1989 International Cancer Research Centre (IARC) classifies gasoline off-gas as a 2B human carcinogen, Neither was able to confirm and reach consensus. In order to understand the toxic action mechanism of gasoline tail gas and the role of oxidative damage in its toxic mechanism, the relationship between the exposure of gasoline tail gas and the occurrence of cancer is further revealed, and the experimental basis is provided for the relationship between the exposure of gasoline tail gas and the occurrence of cancer. The effects of gasoline tail gas on the oxidative damage of multi-organ tissue cells in vitro cultured cells and trachea were investigated by using organic extracts of condensate, particulate matter and semi-volatile organic compound (SVOC) of gasoline tail gas as processing factors. In vitro test, human lung adenocarcinoma epithelial cell line A549 cell was used as the research object, and the tail gas shadow of gasoline was determined by MTT assay, 2-day, 7-day-dichloro-bishydrogen fluorescein diacetate (DCFH-DA) active oxygen measurement experiment, antioxidant test, micronucleus test and comet assay. In response to cell survival, the oxidative damage of active oxygen species and lipids, the activity of antioxidant enzymes, The results show that the tail gas of gasoline can reduce the cell survival rate, induce the generation and accumulation of active oxygen species in the cells, cause the oxidative damage of lipid and decrease the activity of antioxidant enzymes, and can lead to the increase of DNA single-strand breaks. The damage of the chromosome shows that the tail gas of gasoline has obvious cytotoxicity and genotoxicity, and oxidative stress may be its poison. In addition, the effect of reducing glutathione (GSH) on the tail gas toxicity of gasoline indicates that GSH can lower the tail of gasoline The results showed that the cell survival rate, reactive oxygen content and lipid peroxidation, the decrease of antioxidant enzyme activity and the fragmentation of DNA single strand in GSH pretreatment group were observed. lower than the non-intervention group. The result further suggests that oxidative damage occurs in the poison effect of gasoline tail gas from the other side In vivo, the three-phase organic extracts of gasoline tail gas were exposed to SD rats by air-gas instillation, and then lung, brain, liver and testis were treated according to EPA's regulations on new fuel toxicity evaluation. The results showed that the oxidative damage of lipid, protein and nucleic acid in lung tissue of rats and the decrease of antioxidant enzyme activity could be caused by the tail gas of gasoline, and the pathological tissue sections were observed. The results show that the exposure of gasoline tail gas can lead to 8-hydroxyproline DN in lung tissues. The changes of cell organelle structure of lung tissue were observed by electron microscope, and the damage of mitochondria in various cells of lung tissue was found to be obvious. In the same vein, the exposure of gasoline tail gas leads to lipid peroxidation products (MDA) and protein oxidative damage products in organs such as brain, liver and testis. The content of zinc finger protein (CP) increased, the activity of superoxide dismutase (SOD) and glutathione peroxidase (GPx) decreased (except brain tissue). The results of animal experiments indicate that the lung is its main target organ after exposure to respiratory tract, but other organs, such as brain, liver and testis, can also be involved, indicating that the injury after exposure of gasoline tail gas is multi-organ, and oxidative stress can The results of in vitro experiments show that the oxidative damage of biological macromolecules such as lipids, nucleic acids and proteins of multiple organs can be caused after exposure of gasoline tail gas, and can resulting in a change in the amount of DNA damage repair enzyme OGG1
【學(xué)位授予單位】：四川大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2007
【分類號(hào)】：R363
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本文編號(hào)：2267894
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