【摘要】：硒是動物機體維持正常生理活動所必需的一種營養(yǎng)微量元素。動物體內(nèi)的硒主要來自食物攝入。硒元素主要通過硒蛋白的形式在動物體內(nèi)發(fā)揮其生物學功能。硒缺乏可以導致氧化應激并引發(fā)不同組織的損傷,如肌肉壞死、胰腺萎縮、免疫或神經(jīng)損傷。以前的研究證實,硒缺乏會引起雞滲出性素質(zhì)病變,損害雞腸道、胰腺、心臟、骨骼肌等器官和組織的生物學功能并能影響硒蛋白在這些組織中的表達。雞的免疫器官(胸腺、脾臟、法氏囊)也是硒缺乏的靶器官,在其體內(nèi)體液免疫和細胞免疫系統(tǒng)中扮演重要角色。目前為止,關于硒缺乏對肉雞免疫器官組織結構和功能以及其中硒蛋白表達量的影響的研究尚未見報道。本試驗中,將150只1日齡肉雞進行隨機分為2組。一組飼喂來自中國黑龍江省缺硒地區(qū)的低硒日糧(硒含量為0.008mg/kg),構建滲出性素質(zhì)雞模型;另一組飼喂添加硒的正常日糧(硒含量為0.2mg/kg),作為對照組。按照標準化常規(guī)飼養(yǎng)兩組雛雞,自由采食,供應飲水,直至低硒組肉雞出現(xiàn)滲出性素質(zhì)癥狀(約為20日齡),對兩組肉雞進行剖檢采樣。通過H.E染色對肉雞免疫器官進行組織病理學觀察,利用實施定量PCR技術檢測肉雞免疫器官中23種硒蛋白和細胞因子的mRNA水平,通過統(tǒng)計學方法研究硒缺乏對肉雞免疫器官組織結構和功能以及其中硒蛋白表達量的影響,以及其可能的發(fā)生機制,試驗結果顯示:(1)低硒日糧會引起肉雞免疫器官組織結構發(fā)生改變,提示缺硒將進一步損傷肉雞免疫器官的生物功能。(2)低硒日糧誘導肉雞免疫器官中23種硒蛋白mRNA表達水平降低,表明飼喂低硒日糧將直接影響肉雞免疫器官中相關硒蛋白的表達,其中抗氧化硒蛋白的表達量受低硒日糧影響更為嚴重。(3)缺乏能改變?nèi)怆u免疫器官中細胞因子白介素-4、白介素-6、白介素-10和白介素-17的分泌,提示缺硒可誘導肉雞免疫器官中免疫功能降低。
[Abstract]:Selenium is a kind of nutritive trace element necessary for animal body to maintain normal physiological activities. Selenium in animals comes mainly from food intake. Selenium plays its biological role in animals mainly through the form of selenium protein. Selenium deficiency can lead to oxidative stress and damage to different tissues, such as muscle necrosis, pancreatic atrophy, immune or nerve damage. Previous studies have confirmed that selenium deficiency can cause exudative diathesis of chicken, damage the biological function of organs and tissues such as intestine, pancreas, heart and skeletal muscle, and affect the expression of selenium protein in these tissues. Chicken immune organs (thymus, spleen, bursa of Fabricius) are also target organs of selenium deficiency and play an important role in humoral and cellular immune system. So far, the effects of selenium deficiency on the structure and function of immune organs and the expression of selenium protein in broilers have not been reported. In this experiment, 150 1-day-old broilers were randomly divided into 2 groups. One group was fed low selenium diet (selenium content was 0.008mg/kg) from the selenium deficiency area of Heilongjiang Province of China, and the other group was fed normal diet (selenium content was 0.2mg/kg), which was used as control group. Two groups of chicks were raised according to the standard routine, fed freely and supplied with drinking water, until the broilers of low selenium group had exudative quality symptoms (about 20 days old), and the two groups of broilers were sampled by dissection. The histopathological changes of immune organs of broilers were observed by H. E staining. The mRNA levels of 23 kinds of selenium proteins and cytokines in immune organs of broilers were detected by quantitative PCR technique. The effects of selenium deficiency on the structure and function of immune organs and the expression of selenium protein in broilers were studied by statistical method, and the possible mechanism of selenium deficiency was also studied. The results showed that: (1) low selenium diet could cause changes in the tissue structure of immune organs of broilers, suggesting that selenium deficiency would further damage the biological function of immune organs of broilers, (2) low selenium diet induced the decrease of mRNA expression level of 23 kinds of selenium proteins in immune organs of broilers. The results showed that selenium deficiency diet could directly affect the expression of selenium related protein in immune organs of broilers. The expression of antioxidant selenium protein was more seriously affected by low selenium diet. (3) deficiency could change the secretion of cytokines interleukin-4, interleukin-6, interleukin-10 and interleukin-17 in immune organs of broilers. It was suggested that selenium deficiency could induce the decrease of immune function in immune organs of broilers.
【學位授予單位】：東北農(nóng)業(yè)大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：S831.5
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本文編號：2240868