【摘要】：本研究旨在研究不同維生素A添加水平對LPS和NH3免疫應激作用下肉仔雞呼吸道黏膜免疫的影響,為確定維生素A在維持黏膜完整性的作用機制提供理論依據。試驗首先研究了日糧維生素A的確可以影響?zhàn)つっ庖吖δ?之后又考察了LPS的黏膜免疫應激作用。最后研究測定了維生素A在LPS和NH3存在狀態(tài)下對黏膜免疫功能的影響。試驗一,選取1日齡AA肉雞,按日糧維生素A梯度不同分為4個處理:0 IU/kg、1500 IU/kg、6000 IU/kg、12000 IU/kg。試雞自由采食與飲水,飼養(yǎng)7d。結果發(fā)現:不同維生素A添加量對血清Ig A以及BALF Ig A和黏蛋白的生成產生了顯著性差異,當維生素A添加量為0或過高時都會抑制杯狀細胞、IgA和黏蛋白的產生。并且對TNF-α、TGF-α、EGFR、IL-13、TGF-β細胞因子的基因表達產生了顯著性的影響。研究證明:維生素A的確參與了呼吸道黏膜免疫調控,并能通過影響相關細胞因子的基因表達調控Ig A和黏蛋白的產生。試驗二,選取7日齡AA肉雞,試驗組LPS按雞體重1mg/kg劑量霧化,對照組用相同體積生理鹽水霧化,試驗雞暴露2小時,在4/8h之后采樣。結果顯示:LPS抑制了BALF黏液量的產生,血清和BALF IgA濃度有上升的趨勢,且升高了肺組織Ig A的蛋白表達量。結果表明:LPS能夠激發(fā)呼吸道黏膜免疫應激反應。試驗三,根據試驗一和試驗二的結果,同時結合生產過程中NH3是誘導家禽呼吸道疾病的最主要的因素之一。用LPS和NH3模擬免疫應激,同時添加維生素A,研究維生素A及其LPS和NH3對肉雞呼吸道黏膜免疫的影響。試驗選取1日齡AA肉仔雞,日糧按維生素A水平不同分為1500IU/kg、6000IU/kg,14日齡時分別用LPS(1mg/kg)和NH3(100ppm)暴露處理2h,在4h之后采樣。結果顯示:SEM顯示氨氣、LPS處理呼吸道都造成氣道上皮纖毛脫落稀少,NH3和LPS雙重刺激造成纖毛脫落較嚴重,且造成大面積的上皮細胞損傷,日糧添加維生素A可以小面積緩解纖毛的脫落。此外,日糧與NH3對血清Ig A水平、BALF黏蛋白濃度和肺TNF-α、TGF-α、TGF-βmRNA表達水平存在著交互作用,日糧與LPS對BALF黏蛋白濃度、肺組織Ig A蛋白表達和EGFR mRNA表達水平存在著交互作用。以上研究表明:維生素A可通過調控Ig A和黏蛋白的生成,進而影響呼吸道黏膜免疫的功能。維生素A在調控黏膜免疫方面與LPS/NH3存在著一定的交互作用,且維生素A有可能是通過影響細胞因子的基因表達進而緩解LPS/NH3對呼吸道的應激作用,具體的調控機制還需進一步探究。維生素A存在潛在的緩解肉仔雞呼吸道疾病的作用,對我國AA肉雞的生產具有一定的指導作用。
[Abstract]:The purpose of this study was to study the effects of different vitamin A supplementation levels on respiratory mucosal immunity of broilers under LPS and NH3 immune stress, and to provide theoretical basis for determining the mechanism of vitamin A in maintaining mucosal integrity. The effect of dietary vitamin A on mucosal immune function was studied firstly, and then the mucosal immune stress of LPS. Finally, the effects of vitamin A on mucosal immune function in the presence of LPS and NH3 were measured. In experiment 1, 1 day old AA broilers were divided into 4 treatments according to dietary vitamin A gradient: 0 IU/kg,1500 IU/kg,6000 IU/kg,12000 IU/kg.. The chickens were fed and drank freely for 7 days. The results showed that there were significant differences in the production of serum Ig A, BALF Ig A and mucin with different vitamin A supplementation, and the production of goblet cells, IgA and mucin was inhibited when the vitamin A concentration was 0 or too high. The gene expression of TNF- 偽, TGF- 偽 and EGFR,IL-13,TGF- 尾 was significantly affected. It has been proved that vitamin A is involved in the regulation of respiratory mucosal immunity and regulates the production of Ig A and mucin by affecting the gene expression of related cytokines. In the second experiment, 7-day-old AA broilers were selected. The LPS of the experimental group was atomized according to the weight of 1mg/kg, while the control group was nebulized with the same volume of normal saline. The chickens were exposed for 2 hours and sampled after 4 / 8 h. The results showed that LPS inhibited the production of BALF mucus, increased serum and BALF IgA concentrations, and increased the expression of Ig A protein in lung tissue. The results showed that LPS could stimulate the respiratory mucosal immune stress response. In experiment 3, according to the results of experiment 1 and experiment 2 and combined with NH3 during production, NH3 is one of the most important factors in inducing respiratory diseases in poultry. The effects of vitamin A and its LPS and NH3 on respiratory mucosal immunity in broilers were studied by simulating immune stress with LPS and NH3 and adding vitamin A at the same time. The diets of 1-day-old AA broilers were divided into 1500 IU / kg / kg ~ (6 000) ~ (-1) ~ (-1) U / kg ~ (-1) / kg ~ (-1) ~ (-1) ~ (-1) ~ (-1) LPS (1mg/kg) and NH3 (100ppm) exposure for 2 h, and then sampled 4 h later. The results showed that ammonia gas was detected by SEM and respiratory tract was treated with LPS. The results showed that the airway epithelial cilia shedding was rare, and the double stimulation of NH3 and LPS caused severe cilia exfoliation, and caused extensive epithelial cell injury. Dietary vitamin A supplementation can alleviate cilia in a small area. In addition, there was interaction between diet and NH3 on serum Ig A level, BALF mucin concentration and lung TNF- 偽, TGF- 偽, TGF- 尾 mRNA expression levels. There is interaction between Ig A protein expression and EGFR mRNA expression in lung tissue. These results suggest that vitamin A can affect the mucosal immune function of respiratory tract by regulating the production of Ig A and mucin. Vitamin A has some interaction with LPS/NH3 in regulating mucosal immunity, and vitamin A may alleviate the stress of LPS/NH3 on respiratory tract by affecting gene expression of cytokines. The specific regulation and control mechanism needs to be further explored. Vitamin A has a potential role in relieving respiratory tract diseases in broilers and has a certain guiding effect on the production of AA broilers in China.
【學位授予單位】：山東農業(yè)大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：S831.5

【參考文獻】

相關期刊論文 前1條

1 牛秋紅;褚學英;崔小亮;徐麗;劉芳俠;孫琳;;黏蛋白對氣道黏液高分泌的抑制及其機制研究[J];生物技術;2011年02期

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本文編號：2370484