發(fā)布時(shí)間：2018-06-22 09:04

  本文選題：毒死蜱 + 亞中毒閾劑量�。� 參考：《中南大學(xué)》2006年博士論文

【摘要】： 目的：“安全劑量”的有機(jī)磷農(nóng)藥對(duì)人體真無(wú)害嗎?這是涉及疾病控制和公共衛(wèi)生的一個(gè)重要的問(wèn)題。本研究探討大鼠新生期暴露亞中毒閾劑量(“安全劑量”)有機(jī)磷農(nóng)藥毒死蜱(Chlorpyrifos，CPF)，對(duì)成年期中腦黑質(zhì)多巴胺能神經(jīng)元和神經(jīng)行為的影響。 方法：出生11天SD大鼠138只，隨機(jī)分為CPF組(n=46)、對(duì)照組(n=92)。對(duì)照組又分為溶劑二甲亞砜(dimethysulfoxide，DMSO)對(duì)照組(n=46)和生理鹽水(normal sodiu，NS)對(duì)照組(n=46)。大鼠出生11-14天經(jīng)腹部皮下注射亞中毒閾劑量(以下簡(jiǎn)稱“亞劑量”，5mg／kg．d)CPF，制作新生SD大鼠暴露CPF動(dòng)物模型。脂溶性的CPF溶于溶劑DMSO中給藥。對(duì)照組分別以DMSO、NS替代CPF。各組給藥體積均為1ml／kg．d。給次給藥后嚴(yán)密觀察12小時(shí)有無(wú)急性有機(jī)磷農(nóng)藥中毒癥狀。設(shè)出生后15天、20天、30天、60天共四個(gè)觀察時(shí)點(diǎn)。透射電鏡觀察CPF對(duì)小膠質(zhì)細(xì)胞超微形態(tài)結(jié)構(gòu)影響；免疫組織化學(xué)方法檢測(cè)中腦黑質(zhì)多巴胺能神經(jīng)元酪氨酸羥化酶(TH)及海馬星形膠質(zhì)細(xì)胞膠質(zhì)纖維酸性蛋白(GFAP)表達(dá)；RT-PCR檢測(cè)中腦黑質(zhì)小膠質(zhì)細(xì)胞CD11bmRNA及膠質(zhì)細(xì)胞系源性神經(jīng)營(yíng)養(yǎng)因子GDNFmRNA的表達(dá)；酶聯(lián)免疫吸附方法檢測(cè)腦TNF-α、IL-1β水平；高架十字迷[笛櫧攔瀾孤撬健Ｋ兇柿喜捎肧PSS l 2．O統(tǒng)計(jì)軟件包進(jìn)行數(shù)據(jù)處理。所有數(shù)據(jù)用均值±標(biāo)準(zhǔn)差((?)±S)表示，首先采用單因素方差分析，，方差齊時(shí)采用最小顯著差法t檢驗(yàn)，方差不齊時(shí)用Dunnett’s t檢驗(yàn)。P＜0.05為差異有顯著性。 結(jié)果：新生鼠暴露亞劑量CPF未見(jiàn)急性有機(jī)磷農(nóng)藥中毒癥狀。觀察至成年期有如下重要發(fā)現(xiàn)： 1．CPF在中腦黑質(zhì)急速誘導(dǎo)小膠質(zhì)細(xì)胞活化，在超微結(jié)構(gòu)小膠質(zhì)細(xì)胞由靜息狀態(tài)轉(zhuǎn)變?yōu)榫哂型淌勺饔玫募せ顮顟B(tài)，上調(diào)CD11b mRNA表達(dá)在暴露CPF早期(出生15天)比晚期(出生20天)更明顯(P＜0.05)，增加炎癥細(xì)胞因子TNF-α表達(dá)(P＜0.01)，但對(duì)IL-1β無(wú)影響(P＞0.05)。 2．暴露CPF下調(diào)中腦黑質(zhì)GDNFmRNA表達(dá)并使中腦黑質(zhì)TH陽(yáng)性細(xì)胞表達(dá)(出生30天、60天)下降(P＜0.05)。 3．新生鼠暴露CPF誘導(dǎo)海馬星形膠質(zhì)細(xì)胞活化(P＜0.05)并增加成年期(出生60天)焦慮水平(P＜0.01)。 4．DMSO與NS比較，抑制小膠質(zhì)細(xì)胞活性，減少CD11bmRNA表達(dá)并增加GDNFmRNA的表達(dá)(P＜0.05)。 結(jié)論：本研究首次證實(shí)，新生期動(dòng)物暴露亞劑量有機(jī)磷農(nóng)藥CPF后，通過(guò)中腦黑質(zhì)小膠質(zhì)細(xì)胞激活，增加TNF-α表達(dá)，同時(shí)減少GDNFmRNA表達(dá)，誘導(dǎo)成年期中腦黑質(zhì)多巴胺能神經(jīng)元損害。這個(gè)發(fā)現(xiàn)可以為神經(jīng)退行性疾病，特別是對(duì)帕金森氏病(Parkinson’s disease，PD)的病因提供重要的線索。同時(shí)還發(fā)現(xiàn)，新生期動(dòng)物暴露亞劑量CPF后，導(dǎo)致成年期焦慮水平增加，同時(shí)伴隨海馬星形膠質(zhì)細(xì)胞激活。這個(gè)發(fā)現(xiàn)主要證明在新生兒期暴露環(huán)境化學(xué)污染物，可以在成年期引起神經(jīng)精神紊亂，從而部分的闡述神經(jīng)精神疾病的發(fā)病機(jī)理。 此外，本研究還有一個(gè)出乎預(yù)料的發(fā)現(xiàn)，DMSO通過(guò)在中腦抑制小膠質(zhì)細(xì)胞活性，增加GDMFmRNA表達(dá)，可能對(duì)多巴胺能神經(jīng)元具有保護(hù)作用。這個(gè)重要的發(fā)現(xiàn)，對(duì)神經(jīng)退行性疾病，特別是對(duì)帕金森氏病有潛在的治療意義。
[Abstract]:Objective: is the "safe dose" of organophosphorus pesticides really harmless to the human body? This is an important problem involved in disease control and public health. This study explores the threshold dose ("safe dose") of Chlorpyrifos (CPF) of the neonatal exposure subthreshold dose ("safe dose"), and to the dopaminergic neurons and deity of the midbrain substantia nigra. The effect of behavior.
Methods: 138 SD rats born 11 days were randomly divided into group CPF (n=46) and control group (n=92). The control group was divided into two methyl sulfoxide (dimethysulfoxide, DMSO) control group (n=46) and normal saline (normal sodiu, NS) control group (n=46). The subcutaneous injection of subcutaneous intoxication threshold dose (hereinafter referred to as "subdose") in the abdominal subcutaneous injection (hereinafter referred to as "sub dose") in the rats was born. CPF, the animal model of neonatal SD rats exposed to CPF was made. The fat soluble CPF was dissolved in the solvent DMSO. The control group was DMSO, NS instead of CPF., the volume of each group was 1ml / kg.d.. After 12 hours, there were no acute organophosphorus pesticide poisoning symptoms. Four observation time points were set up after birth, 20 days, 30 days, and 60 days. The ultrastructural effects of CPF on the ultrastructure of microglia were observed by electron microscopy. Immunohistochemical method was used to detect the expression of dopaminergic tyrosine hydroxylase (TH) and glial fibrillary acidic protein (GFAP) in the hippocampal astrocytes. RT-PCR was used to detect microglia microglia CD11bmRNA and glial cell derived neurotrophic factors in the middle brain The expression of subGDNFmRNA; enzyme-linked immunosorbent assay for the detection of brain TNF- alpha, IL-1 beta, and the data processing of the viaduct cross fan [? Seylis Castanopsis, K? Kenzo persimmon with PSS L 2.O statistical package. All data were expressed with mean mean standard deviation ((?) + S), and the single factor variance analysis was used first and the least significant difference method was used in the variance. T The test showed that when the variance was not homogeneous, Dunnett 's t test was used to test.P < 0.05, the difference was significant.
Results: no acute organophosphorus pesticide poisoning symptoms were found in neonatal rats exposed to sub dose CPF.
1.CPF induced the activation of microglia rapidly in the mesencephalic substantia nigra, and the ultrastructural microglia changed from resting state to phagocytic activation state, and up regulation of CD11b mRNA expression was more obvious (P < 0.05) at the early stage of exposure to CPF (P < 0.05), and increased the expression of inflammatory cytokine TNF- alpha (P < 0.01), but IL-1 beta (P < 0.01). No effect (P > 0.05).
2. exposure to CPF reduced the expression of GDNFmRNA in substantia nigra and decreased the expression of TH positive cells in the substantia nigra (30 days, 60 days) (P < 0.05).
3. neonatal rats exposed to CPF induced hippocampal astrocyte activation (P < 0.05) and increased anxiety level in adulthood (60 days) (P < 0.01).
Compared with NS, 4.DMSO inhibited the activity of microglia, reduced the expression of CD11bmRNA and increased the expression of GDNFmRNA (P < 0.05).
Conclusion: This study is the first to confirm that after exposure to subdose organophosphorus pesticide CPF in newborn animals, the activation of mesencephalic nigral microglia increases the expression of TNF- A and reduces the expression of GDNFmRNA, and induces damage to dopaminergic neurons in the midbrain of the midbrain. This discovery may be a neurodegenerative disease, especially for Parkinson's disease (Park The etiology of inson 's disease (PD) provides important clues. It is also found that neonatal exposure to a sub dose of CPF leads to increased anxiety in adulthood and the activation of astrocytes in the hippocampus. This discovery is mainly a discovery that exposes environmental chemical contaminants in the newborn period and can cause neuropsychiatric disorders in adulthood. The pathogenesis of neuropsychiatric disorders is described in part.
In addition, there is an unexpected discovery that DMSO may have protective effects on dopaminergic neurons by inhibiting the activity of microglia in the middle brain and increasing the expression of GDMFmRNA. This important discovery is of potential therapeutic significance for neurodegenerative diseases, especially for Parkinson's disease.
【學(xué)位授予單位】：中南大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2006
【分類號(hào)】：R363

【引證文獻(xiàn)】

相關(guān)碩士學(xué)位論文 前3條

1 黃敏;暴露亞中毒閾劑量毒死蜱對(duì)新生鼠中腦黑質(zhì)多巴胺能神經(jīng)元線粒體的影響[D];中南大學(xué);2011年

2 劉羅慧;新生鼠暴露亞中毒閾劑量毒死蜱誘導(dǎo)腦組織氧化損傷[D];中南大學(xué);2008年

3 谷芬;新生鼠暴露低劑量毒死蜱后對(duì)脂多糖所致免疫反應(yīng)的影響[D];中南大學(xué);2009年

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