本文關(guān)鍵詞： 二氧化硫衍生物 秀麗線蟲 毒性效應(yīng)　出處：《華中師范大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：二氧化硫(SO_2)是形成霧霾主要大氣污染物之一。其毒害作用主要是通過在機體體液中轉(zhuǎn)化成其體內(nèi)衍生物(亞硫酸鹽和亞硫酸氫鹽),然后隨血液分布全身,從而對機體各種細(xì)胞、組織造成傷害。由于SO_2及其衍生物是一種全身性的毒物,人和動物長期暴露于SO_2污染的大氣環(huán)境下,其健康受到嚴(yán)重的威脅。因此,研究SO_2的供體(SO_2衍生物)對機體毒害作用的機理是目前本領(lǐng)域的研究熱點,具有重要的理論和現(xiàn)實意義。為探明SO_2衍生物對模式生物秀麗線蟲(Caenorhabditis elegans)的毒性效應(yīng)及其毒理機制,本文將線蟲暴露于不同濃度的SO_2衍生物(3.2 mL、32 mg/L和320 mg/L)24 h,然后從生物學(xué)、生物化學(xué)和氧化應(yīng)激三個方面展開研究。在生物學(xué)方面,檢測了線蟲的生殖能力(包括產(chǎn)卵第二天線蟲子宮內(nèi)懷卵量、總產(chǎn)卵量及其子代數(shù)目/卵孵化率)、壽命(最長壽命與平均壽命)及生長發(fā)育(體長與體寬)指標(biāo);在生化方面,檢測了線蟲腸道內(nèi)脂褐質(zhì)的積累及細(xì)胞凋亡情況;在氧化應(yīng)激方面,用試劑盒測定了線蟲體內(nèi)總抗氧化能力(T-AOC)活性和丙二醛(MDA)的含量。最后對數(shù)據(jù)進(jìn)行統(tǒng)計分析得到以下結(jié)果。1、SO_2衍生物暴露導(dǎo)致線蟲蟲體縮短變寬、生殖力下降、壽命縮短。(1)暴露于中、高濃度(32 mg/L和320 mg/L)的線蟲其體長極顯著性縮短(p0.01)、體寬極顯著變寬(p0.01),此外線蟲外陰出現(xiàn)畸形發(fā)育;(2)暴露于5O2衍生物的線蟲各個生殖指標(biāo)均隨著SO_2衍生物濃度上升而下降。相對于對照組,暴露組(3.2 mL、32 mg/L和320mg/L)產(chǎn)卵第二天的線蟲子宮內(nèi)懷卵量分別減少了3.74%、8.29%、32.71%(p0.01);總產(chǎn)卵量分別減少了 4.82%、8.94%(p0.05)和 22.97%(p0.01);子代數(shù)目分別減少了 9.30%(p0.05)、24.87%(p0.01)和42.32%(p0.01),即卵的孵化率分別極顯著下降了 5%、17.89%、25.98%(p0.01);(3)對線蟲壽命的影響表現(xiàn)為:暴露組(3.2 mL、32 mg/L和320mg/L)的線蟲平均壽命分別縮短了 0.34天、5.34天(p0.01)和7天(p0.01),最大壽命分別縮短了 3天(p0.05)、6.33天(p0.01)和10.67天(p0.01)。2、對線蟲腸道內(nèi)自發(fā)熒光密度定量分析得知,暴露于中、高濃度(32mg/L和320mg/L)的線蟲腸道內(nèi)脂褐質(zhì)含量有極顯著的增加(p0.01),熒光密度分別是對照組的1.19倍和1.28倍。此外,SO_2衍生物暴露誘導(dǎo)線蟲發(fā)生細(xì)胞凋亡。3、暴露于不同濃度SO_2衍生物均降低了線蟲T-AOC活性,且中、高濃度(32 mg/L和320 mg/L)出現(xiàn)極顯著降低(p0.01),分別下降了 33.02%和65.42%。而中、高濃度(32mg/L和320mg/L)極顯著增加了 MDA含量(p0.01),分別是對照組的2.1、3.52倍。本文首次進(jìn)行SO_2衍生物對秀麗線蟲毒性效應(yīng)的研究。結(jié)果表明,SO_2衍生物暴露影響線蟲的發(fā)育,體形呈粗短型(體長縮短、體寬變寬),并出現(xiàn)畸形發(fā)育;導(dǎo)致線蟲總產(chǎn)卵量減少、孵化率降低,從而使子代數(shù)目顯著減少;誘導(dǎo)線蟲腸道內(nèi)脂褐質(zhì)含量增多,標(biāo)志著毒物加快線蟲的衰老速度而導(dǎo)致其壽命縮短;并引起細(xì)胞凋亡和氧化應(yīng)激(T-AOC活性下降、MDA含量增加)。綜上所述,SO_2衍生物對線蟲具有多重生物毒性,其毒性機制可能與降低線蟲體內(nèi)T-AOC活性、導(dǎo)致自由基大量積累而引起氧化損傷有關(guān)。以上研究成果可為進(jìn)一步探討SO_2衍生物的毒性機制,尋找有效預(yù)防SO_2及其衍生物中毒的方法提供理論依據(jù)。
[Abstract]:Sulfur dioxide (SO_2) is one of the main atmospheric pollutants of haze formation. The toxicity is mainly through the body into derivatives in body fluids in (sulfite and bisulfite), and then with the blood distribution of the body, so the body cells, tissue damage due to SO_2 and its derivatives is a kind of systemic poison atmospheric environment, human and animal exposure to SO_2 pollution, the health is threatened seriously. Therefore, the research of donor SO_2 (SO_2 derivatives) on the mechanism of toxic action is the research hot point in this field, it has important theoretical and practical significance. In order to investigate the SO_2 derivatives on the model organism C.elegans (Caenorhabditis elegans) the toxic effects and toxicological mechanisms, the nematodes were exposed to different concentrations of SO_2 derivatives (3.2 mL, 32 mg/L and 320 mg/L) 24 h, and then from the biology, biochemistry Research on three aspects and oxidative stress. In biology, the detection of nematode reproductive capacity (including spawning second worm eggs of antenna in the womb, the total fecundity and egg hatching rate / number), life (the longest life and life expectancy) and growth (body length and width index); in biochemistry, detect the accumulation and apoptosis of intestinal nematode lipofuscin in oxidative stress; total antioxidant capacity in vivo, nematodes were determined by ELISA Kit (T-AOC) activity and malondialdehyde (MDA) content. Finally, the data for statistical analysis results in the following.1, SO_2 derivatives exposure to nematode body shortening variable width, fertility decline, shorten the life. (1) exposed in high concentration (32 mg/L and 320 mg/L) of the nematode body length was significantly shortened (P0.01), body width significantly variable width (P0.01), this nematode vulva appeared abnormal growth; (2) exposure to 5 O2琛嶇敓鐗╃殑綰胯櫕鍚勪釜鐢熸畺鎸囨爣鍧囬殢鐫，

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