維生素e與應激反應外文翻譯

1、<p>　　Vitamin E and stress response</p><p>　　Stress (stress) refers to the sum of nonspecific response to external or internal very stimuli, caused by stress factors known as stress factors or stressors

2、 (stressor). The mobilization of body tissues and organs to deal with, to adapt to the series of responses to stress stimuli showed that general adaptation syndrome (GAS). It is organized as follows: ① the physiological

3、changes of adrenocorticotropic hormone (ACTH) production and increased release of, anterior pituitary enlargement. ② adrena</p><p>　　The modern intensive livestock production, automation, in order to maximiz

4、e the level of livestock and poultry production, increase economic efficiency, to livestock and poultry as "production machine". The production process and technical measures adopted are often contrary to the a

5、nimal's physiological needs. The resulting stress leads to decrease of slow growth, reduced fecundity, productivity and product quality variation, the immunity of livestock and poultry, causing great harm to livestoc

6、</p><p>　　1,the stress response mechanism</p><p>　　The mechanism of stress response is a complex process, according to the Canadian pathologist Hans Selye stress theory, from the stress state of

7、 view, can be divided into three periods: alert period (emergency reaction stage), resistance (resistancestage) and failure stage (exhaustion stage). The alert period. The body has not yet received the adaptation period,

8、 the body is early response to stressors. According to the physiological and biochemical changes of different, this period can be divided</p><p>　　2. The clinical symptoms of stress</p><p>　　Bec

9、ause the source of stress intensity, duration, chicken breed, age and nutritional status, stress the variety of clinical symptoms, basically divided into the following three types.</p><p>　　2, 1 sudden death

10、 of stress syndrome</p><p>　　Chicken in the catch, frightened, vaccine reaction or extrusion strong stressor stimulation, not showing any symptoms, sudden death. This is due to strong stimulation, "symp

11、athetic - adrenal system activity," caused by shock or circulatory collapse and sudden death.</p><p>　　2, 2 acute stress syndrome</p><p>　　Mainly due to stress caused by long time strong st

12、imulation, common are the following: ① heat stress syndrome. The temperature is too high, the hot weather, the crowded transportation, water, chicken body heat too much, difficult heat dissipation, the performance diffic

13、ulty breathing, mouth breathing, heart rate, body temperature, crown beard flushing cyanosis, muscle tremors, foaming at the mouth, chicken prone to acute bronchial pneumonia and death. ② convulsive stress. Fight, noise,

14、 capture, </p><p>　　2, 3 chronic stress syndrome</p><p>　　By the stress intensity of the long-term repeated stimulation. For example, the lack of nutrition, competition among individuals, raisin

15、g no rules, and hunger and satiety, Sherwin sometimes hot and sometimes cold, bacterial, fungal infection, the body continues to make adaptation efforts, forming the cumulative effect of adverse effect of chicken, appeti

16、te, causing growth retardation, weight reduction, laying rate drop, the hatching rate. Weakened immune response and defense capabilities, easy t</p><p>　　3. Stress damage of chicken</p><p>　　Nor

17、mal chicken has the ability to cope with stress from damage, but this ability is limited. The cumulative effect of stress factor or stress beyond protecting threshold, will change from the physiological process for the p

18、athological process. Endanger mainly have the following aspects.</p><p>　　3.1Production performance</p><p>　　Stress, protein, carbohydrate, fat and increased catabolism, produce more energy to m

19、eet the immediate needs, such as heat, accelerated breathing, heartbeat, and fled, and these nutrients for growth, the original weight, immune function, so the indirect effects of the production performance of chickens,

20、performance poult dysplasia, survival rate is low; poultry and egg laying rate drop, egg quality is low, eggs, small deformation, eggshell thinning, brittle, surface roughness, broken egg rate, h</p><p>　　3,

21、 2 produce stress syndrome</p><p>　　Manifestations of renal cortical hypertrophy, lassitude, rapid heartbeat, high blood pressure, loss of appetite, reduced sexual function, slow growth, the most serious fro

22、m fear of death.</p><p>　　3, 3 immune resistance</p><p>　　Chicken in the stress, the increase in the secretion of epinephrine, make blood lymphocytes decreased, at the same time, because of incr

23、eased protein catabolism, used to produce immunoglobulin raw material is relatively reduced, the vaccine, antibody formation was reduced, low antibody level in the body, can not achieve the desired effect of the immune.&

24、lt;/p><p>　　3, 4 to induce various diseases</p><p>　　Stress not only make chicken lower only specific immunity in chickens, and non - specific resistance is generally reduced, easy to induce a vari

25、ety of diseases, such as bluecomb disease, chronic respiratory disease, infectious coryza, aspergillosis, bursitis, fowl cholera, ulcerative enteritis.</p><p>　　4, immunological stress</p><p>　　

26、Immunological stress animal is the animal vaccination appear individual allergic, a handful of animal body temperature, some animal anorexia, metabolism, growth, feeding cycle extension phenomenon. Generalized "immu

27、ne" also known as immune challenge in immunology, which inject antigen to stimulate the immune response. In the animal life, there are many factors (including infection, trauma and tumor) can cause immune stress. In

28、 the immunity during stress, cytokines especially produced by monocyte</p><p>　　5、Mechanisms of the immune stress on animal immune system</p><p>　　Mechanisms of the immune stress on animal immun

29、e system is generally thought to be mediated by glucocorticoid. Adrenal cortical hormone can cause immune suppression. In addition, in the process of immune stress, neuroendocrine system activity changed obviously, which

30、 is one of the important factors lead to the change of the function of the immune system. Fan Shaoguang thinks, adrenal cortical hormone mediated stress has a concentration range, he also put under stress, through the ce

31、ntral nervous</p><p>　　In the production process of laying hens, vaccination is epidemic link inevitable, effects on performance is quite significant, is a significant problem for development of intensive, l

32、arge-scale poultry industry. In recent years, immune vaccination caused the chicken immune stress often report. Vitamin E has extensive biological effects on the body, not only has nutrition, and pharmacological effects.

33、 In recent years, the function of vitamin E at home and abroad have done a lot of research, but </p><p><b>　　維生素E與應激反應</b></p><p>　　應激(stress)是指機體對外界或內(nèi)部的各種非常刺激所產(chǎn)生的非特異性反應的總合，引起應激的因素稱為

34、應激因子或應激源(stressor)。機體調(diào)動全身組織器官以對付、適應應激因子的刺激所表現(xiàn)的系列反應稱全身適應綜合癥(簡稱GAS)。其組織生理變化如下：①促腎上腺皮質(zhì)激素 (ACTH)生成量和釋放量增加，垂體前葉腫大。②腎上腺增生腫大。③因皮質(zhì)酮釋放量增加而腎上腺膽固醇分泌減少。④幼禽最敏感的反應是組織淋巴、胸腺、法氏囊和脾臟萎縮；成年雞因受生殖腺類固醇的影響，只有法氏囊萎縮。⑤白細胞發(fā)生變化，表現(xiàn)為淋巴細胞減少，異嗜白細胞增加。⑥血液

35、檸檬酸濃度上升。⑦生長受阻，體重下降。</p><p>　　現(xiàn)代集約化、自動化畜牧生產(chǎn)，為了最大限度地提高畜禽生產(chǎn)水平，增加經(jīng)濟效益，把畜禽當成“生產(chǎn)機器”。所采用的生產(chǎn)工藝和技術措施往往違背了畜禽的生理需要。由此而引起的應激導致畜禽生長發(fā)育緩慢、生產(chǎn)力和繁殖力下降、產(chǎn)品質(zhì)量變差、免疫力減弱，給畜禽生產(chǎn)造成巨大的危害。在現(xiàn)代養(yǎng)殖業(yè)生產(chǎn)中，疫苗對預防、控制和消滅畜禽傳染病發(fā)揮著極其重要的作用，免疫接種一方面保護了動

36、物機體免受病原的侵害，另一方面也作為一種特殊的應激因子引起免疫應激，對機體產(chǎn)生一定的損害，這種損害不僅影響畜禽的生長發(fā)育及生產(chǎn)性能，而且可能造成少數(shù)動物的死亡。</p><p>　　1、應激反應的發(fā)生機制</p><p>　　應激反應的發(fā)生機制是一個復雜的過程，根據(jù)加拿大病理學家Hans Selye的應激學說，從經(jīng)過應激反應的狀態(tài)來看，可分為三個時期：警覺期(emergency react

37、ion stage)、抵抗期(resistancestage)和衰竭期(exhaustion stage)。①警覺期。機體尚未獲得適應期，是機體對應激源的早期反應。根據(jù)生理生化變化的不同，該期又可分為休克相和反休克相。休克相表現(xiàn)為體溫和血壓下降、血液濃縮、神經(jīng)系統(tǒng)抑制、肌肉緊張度降低，進而發(fā)展到組織降解、低血氯、高血鉀、胃腸急性潰瘍，機體抵抗力低于正常水平。休克相可持續(xù)幾分種至24小時。應激反應進入反休克相，機體防衛(wèi)反應得到加強，血壓上

38、升，血鈉和血氯增加，血鉀減少，血糖提高，分解代謝加強，胸腺、脾臟和淋巴系統(tǒng)萎縮，嗜酸性白細胞和淋巴細胞減少，腎上腺皮質(zhì)肥大，機體總抵抗力提高，甚至可高于正常水平。②抵抗期。機體克服了應激源作用而獲得了適應，許多表現(xiàn)與驚恐反應相反，新陳代謝趨于正常，同化作用占優(yōu)勢，血液中白細胞和腎上腺皮質(zhì)激素含量也趨于正常，機體的全身非特異性抵抗力提高到高于正常水平。③衰竭期。表現(xiàn)很象警覺期，但反應程度急劇增</p><p>&l

39、t;b>　　2、應激的臨床癥狀</b></p><p>　　由于應激源的強度、持續(xù)時間、雞的品種、年齡及營養(yǎng)狀態(tài)不同，應激的的臨床癥狀多種多樣，基本上歸納為以下三種類型。</p><p>　　2、1猝死性應激綜合癥</p><p>　　雞在捕抓、驚嚇、疫苗反應或擠壓等強烈的應激源的刺激下，不表現(xiàn)任何癥狀，突然死亡。此乃由于受到強烈刺激，“交感-腎上

40、腺”系統(tǒng)活動增強，引起休克或循環(huán)虛脫而至猝然死亡。</p><p>　　2、2急性應激綜合癥</p><p>　　主要是由于受到長時間較強的應激源刺激引起，常見的有下列幾種：①熱應激綜合癥。雞舍溫度過高，炎熱天氣運輸、擁擠、缺水等，雞體產(chǎn)熱過多，散熱困難，故表現(xiàn)呼吸困難，張口喘息，心跳加快，體溫升高，冠髯潮紅發(fā)紺，肌肉震顫，口吐白沫，雞易發(fā)生急性支氣管肺炎乃至死亡。②致驚應激。爭斗、噪音、

41、捕捉、運輸、混群等過程中受驚，表現(xiàn)頭部羽毛豎起，驚恐不安，緊張、躲藏，食欲不振甚至廢絕，增重緩慢，產(chǎn)蛋率下降，少數(shù)雞發(fā)生死亡。③啄食癖。飼養(yǎng)密度大（擁擠應激)，舍溫過高（熱應激)，光線過強（光應激)，皮膚創(chuàng)傷和出血（創(chuàng)傷應激)，疥癬或其他外寄生蟲寄生（癢應激)等應激源的刺激，可引起應激反應性啄癖；蛋白質(zhì)、維生素、礦物質(zhì)等缺乏所致的營養(yǎng)缺乏性啄癖也是一種應激反應。臨床表現(xiàn)為啄羽、啄肛、啄趾、啄肉、啄蛋。④酉時病。雞每天天黑后2h內(nèi)發(fā)病，稱

42、之為酉時病。酉時是雞歸窩上架的時間，如此時舍內(nèi)暗淡無光，雞上架騷動特別劇烈，急劇聚堆，相互踐踏、擠壓產(chǎn)生應激致死。⑤肌胃損傷。雞的肌胃粘膜發(fā)生糜爛或潰瘍。</p><p>　　2、3慢性應激綜合癥</p><p>　　多由強度不大的應激源長期反復刺激引起。例如營養(yǎng)缺乏，個體間競爭，飼養(yǎng)無規(guī)律，忽饑忽飽，舍溫忽冷忽熱，細菌、霉菌慢性感染等，機體不斷地作出適應性的努力，形成不良的累計效應，影響

43、雞的食欲，致使生長發(fā)育遲緩，增重減少，產(chǎn)蛋率下降，孵化率降低。免疫反應能力和防御能力減弱，容易繼發(fā)感染其他疾病。</p><p><b>　　3、應激對雞的危害</b></p><p>　　正常雞有一定對付應激免遭損害的能力，但這種能力是有限的。應激因子或應激的累加作用超越保護閾限時，就會由生理過程轉變?yōu)椴±磉^程。主要危害有下列幾方面。</p><

44、p><b>　　3、1生產(chǎn)性能降低</b></p><p>　　應激時，蛋白質(zhì)、碳水化合物、脂肪等分解代謝增強，產(chǎn)生更多的能量以應付立即的需要，如熱散發(fā)、加速呼吸、加快心跳、奔逃等，而這些營養(yǎng)物質(zhì)原本用于生長、增重、免疫等功能的，所以間接影響了雞群的生產(chǎn)性能，表現(xiàn)為幼禽發(fā)育不良，成活率降低；蛋禽產(chǎn)蛋率下降，蛋品質(zhì)低下，蛋形變小，蛋殼變薄、變脆，表面粗糙，破蛋率上升，種蛋受精率下降；肉禽

45、生長受阻，體重下降，肉品質(zhì)差，飼料報酬低。</p><p>　　3、2產(chǎn)生應激綜合癥</p><p>　　表現(xiàn)為腎皮質(zhì)肥大，精神不振，心跳加速，血壓升高，食欲減退，性機能降低，生長速度緩慢，最嚴重的因驚恐而死亡。</p><p>　　3、3免疫抵抗力降低</p><p>　　雞在應激時，體內(nèi)腎上腺素分泌增加，使血中淋巴細胞減少，同時因蛋白質(zhì)分

46、解代謝增強，用于產(chǎn)生免疫球蛋白的原料相對減少，此時進行疫苗免疫時，抗體形成減少，體內(nèi)抗體水平低下，不能達到預期的免疫效果。</p><p><b>　　3、4誘發(fā)各種疾病</b></p><p>　　應激不僅使雞只特異性免疫力降低，而且雞只非特異性抗病能力也普遍降低，易誘發(fā)各種疾病，如藍冠病、慢性呼吸道病、傳染性鼻炎、曲霉菌病、滑囊炎、禽霍亂、潰瘍性腸炎等。</

47、p><p><b>　　4、免疫應激</b></p><p>　　動物免疫應激是指動物接種疫苗后出現(xiàn)個別過敏，少數(shù)動物體溫升高，一些動物厭食，代謝改變，生長減緩，飼養(yǎng)周期延長的現(xiàn)象。廣義的“免疫應激”又稱免疫激發(fā)，在免疫學中指注入抗原以激發(fā)免疫應答。在動物生命過程中，有許多因素（包括各種感染、創(chuàng)傷和內(nèi)部腫瘤等）都可引起免疫應激。在免疫應激期間，細胞因子尤其是由單核細胞和巨

48、噬細胞產(chǎn)生的炎性細胞因子IL-1、IL-6和TNF-α可介導系統(tǒng)的炎癥反應，如發(fā)燒、食欲減退等，同時起著營養(yǎng)重分配劑的作用，即可使用于生長和骨骼肌蛋白質(zhì)沉積的養(yǎng)分轉而用于維持機體免疫應答的相關過程。炎性細胞因子的適量產(chǎn)生有利于機體抵御感染，但過多產(chǎn)生則會對機體造成不同程度的損傷。特別是TNF-α在炎癥條件下或某些炎性疾病中都會引起病理反應?，F(xiàn)研究發(fā)現(xiàn)能激活免疫系統(tǒng)的物質(zhì)都有可能刺激機體產(chǎn)生免疫應激（Kelly等，1998）。免疫系統(tǒng)具有

49、優(yōu)先使用養(yǎng)分的能力，當動物發(fā)生免疫應激時，免疫系統(tǒng)活化，釋放出細胞因子(CK)，CK調(diào)節(jié)體內(nèi)代謝過程，影響生長性能和營養(yǎng)需要量及需求模式。研究表明，應激引起的機體變化主要由CK介導。Webel等(1998)給豬注射大腸桿菌脂多糖后提高了IL-6、TNF</p><p>　　5、免疫應激對動物免疫系統(tǒng)的作用機制</p><p>　　免疫應激對動物免疫系統(tǒng)的作用機制一般認為是由糖皮質(zhì)激素介導的

50、。腎上腺皮質(zhì)激素也可導致免疫抑制。另外，在免疫應激過程中，機體神經(jīng)內(nèi)分泌系統(tǒng)功能活動明顯改變，這可能是導致免疫系統(tǒng)功能變化的重要因素之一。范少光認為，腎上腺皮質(zhì)激素介導應激有一個濃度范圍，他還提出在應激條件下，通過中樞神經(jīng)系統(tǒng)的作用，由外周T淋巴細胞產(chǎn)生了一種大分子蛋白質(zhì)，此見解可能對某些免疫功能具有抑制作用，稱為應激免疫抑制蛋白質(zhì)，這為免疫應激造成免疫抑制的研究開辟了新的領域。機體主要通過下丘腦一垂體一腎上腺軸(HPA)系統(tǒng)參與調(diào)節(jié)應

51、激反應，糖皮質(zhì)激素是HPA軸的最終產(chǎn)物，由腎上腺皮質(zhì)束狀帶分泌的主要有皮質(zhì)酮、皮質(zhì)醇等，對免疫系統(tǒng)具有廣泛的作用。機體參與調(diào)節(jié)應激反應的途徑除HPA軸外，還需要垂體一甲狀腺系統(tǒng)參與。在免疫應激狀態(tài)下，可能由于機體內(nèi)腎上腺皮質(zhì)激素和甲狀腺素升高，使機體的細胞免疫功能受到抑制。高文偉等（2001）認為免疫應激后，機體細胞免疫和體液免疫初期受到抑制，后期逐漸恢復。免疫應激后血液中促腎上腺皮質(zhì)激素前期上升，表明血液中ACTH、皮質(zhì)酮對細胞免疫具

52、有明顯的抑制作用。</p><p>　　在蛋雞生產(chǎn)過程中，注射疫苗是不可避免的防疫環(huán)節(jié)，對生產(chǎn)性能的影響相當顯著，是集約化、規(guī)?；B(yǎng)雞業(yè)發(fā)展中值得重視的一個問題。近年來，免疫預防接種引發(fā)雞免疫應激常有報道。維生素E對機體產(chǎn)生廣泛的生物學效應，既有營養(yǎng)作用，又有藥理作用。近年來國內(nèi)外對維生素E的功能進行了大量的研究，但僅限于生產(chǎn)性能、免疫功能與熱應激方面，而對維生素E改善免疫應激的影響方面鮮見報道，特別是維生素E的