氧化应激在硒缺乏致鸡淋巴细胞DNA损伤中的作用

为探讨氧化应激在硒缺乏致鸡淋巴细胞DNA损伤中的作用,选择1日龄健康海兰褐雏鸡120只,随机分为对照组和缺硒组,对照组饲喂硒含量为0.282 mg/kg的饲料,缺硒组饲喂硒含量为0.032 mg/kg的饲料,分别于30、45、60及75日龄采集胸腺、脾脏和法氏囊,检测硒含量、抗氧化功能和淋巴细胞DNA损伤.与对照组比较,缺硒组鸡胸腺、脾脏和法氏囊中硒含量降低;T-AOC,GSH-PX和SoD活性降低,MDA含量升高;淋巴细胞彗星率增加,并呈明显的时间-效应关系;胸腺、脾脏和法氏囊中硒含量、T-AOC、GSH-Px和SOD活性与淋巴细胞DNA损伤呈负相关,MDA含量与其呈正相关.结果表明,氧化应激与硒缺乏致鸡淋巴细胞DNA损伤密切相关.     

复方中药治疗鸡实验性镉中毒的效果研究

为研究复方中药治疗鸡实验性镉中毒的作用机理。试验选取90只鸡随机分为3组(空白对照组、阳性组、中药治疗组),每组30只。空白组饲喂基础日粮，阳性组饲喂基础日粮+40.31 mg/kg氯化镉，中药治疗组饲喂基础日粮+40.31 mg/kg氯化镉+4.7 g/kg复方中药，试验期为90 d。在试验第30 d、60 d、90 d,每组随机取10只鸡，测定体重，采血测血清中丙二醛(MDA)、一氧化氮(NO)的含量，超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、一氧化氮合酶(NOS)的活性，取心脏、肝脏、脾脏、肺脏、肾脏、跖骨检测其镉含量，90 d时另取部分组织器官进行固定制作切片。阳性组鸡体重均显著低于空白对照组鸡体重(P<0.05),中药治疗组鸡体重显著高于阳性组鸡体重(P<0.05);中药治疗组能明显缓解镉引起心脏、肝脏、脾脏、肺脏、肾脏、跖骨炎性细胞浸润，出血等病变；阳性组血清中SOD、GSH-Px、NOS活性NO含量显著低于空白对照组(P<0.05),MDA含量显著高于空白对照组(P<0.05);中药治疗组SOD、GSH-Px、NOS活性NO含量...     

氧化应激在硒缺乏致鸡胰岛β细胞功能损伤中的作用

为探讨氧化应激在硒缺乏致鸡胰岛β细胞功能损伤中的作用,1日龄海兰白蛋鸡200只,随机分为两组,缺硒组饲喂低硒日粮(硒含量为0.032 mg/kg),对照组饲喂正常日粮(硒含量为0.282 mg/kg).分别于30,45,60及75日龄采取全血和胰腺,检测血清和胰腺中抗氧化酶(GSH-Px、SOD、CAT)活性,GSH、MDA含量,放射免疫法检测血清和胰腺中胰岛素和C肽含量,荧光法测定全血和胰腺中硒的含量.结果表明:缺硒组全血和胰腺中硒含量呈下降趋势,血清和胰腺中GSH-Px、T-SOD、CAT活性、GSH含量均低于对照组,MDA含量高于对照组,同时血清胰岛素、C肽含量下降,胰岛C肽及胰岛素分泌贮备减少,均具有统计学意义(P<0.01,P<0.05).缺硒可使鸡血清和胰腺内抗氧化酶活性下降,胰岛β细胞功能降低,表明氧化应激是硒缺乏致鸡胰岛β细胞功能受损的主要原因.     

铝对体外培养鸡脾淋巴细胞一氧化氮代谢和脂质过氧化的影响

本研究分别将0、0.2、0.4、0.6、0.8 mg/mL的AlCl3添加到培养液中,对鸡脾淋巴细胞原代培养24 h,通过检测淋巴细胞内一氧化氮(NO)含量、一氧化氮合酶(NOS)活性、丙二醛(MDA)含量、谷胱甘肽过氧化物酶(GSH-Px)和超氧化物歧化酶(SOD)活性,探究铝对鸡脾淋巴细胞毒性作用机理。结果表明,随着铝浓度的增加,NOS活性增强,NO和MDA含量增加,SOD和GSH-Px活性下降,与对照组相比,组间差异显著(P0.05;P0.01),说明铝可致雏鸡淋巴细胞抗氧化防御功能下降。     

一氧化氮自由基在镉致鸡脾脏淋巴细胞毒性中的作用

为了了解一氧化氮(NO)在镉致鸡脾脏淋巴细胞毒性中的作用,试验以原代培养的鸡脾脏淋巴细胞为材料,在培养体系中加入终浓度为10μmol/L的CdCl2进行培养试验,应用台盼蓝拒染试验和MTT法检测细胞活性,同时测定细胞内NO含量和一氧化氮合酶(NOS)活性。结果表明:随着染镉时间的延长,细胞活性逐渐下降,NO含量与NOS活性在24小时以前呈现升高趋势,在24小时以后呈现下降趋势。说明一氧化氮在镉致鸡脾脏淋巴细胞毒性中发挥着重要作用。     

氟对牛脾淋巴细胞内抗氧化功能和NO代谢的影响

采用常规方法分离培养健康牛脾脏淋巴细胞,用不同浓度氟化钠（NaF）染毒24 h。检测牛脾淋巴细胞内谷胱甘肽过氧化物酶（GSH-Px）、超氧化物歧化酶（SOD）、一氧化氮合酶(NOS)活性及丙二醛（MDA）和一氧化氮（NO）的含量。结果表明,与对照组相比,淋巴细胞内GSH-Px、SOD活性不同程度的降低,而其余各指标均不同程度的升高,且存在着剂量效应关系。由此得出,氟能够导致体外培养牛脾淋巴细胞内抗氧化功能下降,脂质过氧化程度加重,自由基含量增多,对淋巴细胞造成损伤。     

硒缺乏通过TLR4/MyD88/NF-κB信号通路介导鸡胸腺细胞凋亡

本试验旨在探讨硒缺乏是否通过激活Toll样受体信号通路诱导鸡胸腺细胞凋亡。复制硒缺乏模型,将200只1日龄健康的肉鸡随机分为对照组（C组）和缺硒组（L组）,对照组饲喂硒含量0.2 mg·kg^-1的正常日粮,缺硒组饲喂硒含量0.004 mg·kg^-1的缺硒日粮。在15、25、35、45、55日龄时,每组分别选取15只鸡,观察胸腺组织病理形态变化和超微结构变化;检测胸腺组织中TLR4信号转导通路与细胞凋亡相关因子的表达。又建立了MDCC-MSB1（MSB1）细胞硒缺乏模型,并在此基础上设立6个分组：对照（C group）组、缺硒（L group）组、缺硒+转染空质粒（L+pCMV-HA-N）组、缺硒+siRNA阴性对照（L+NCsiRNA）组和缺硒+过表达TLR4（L+pCMV-HA-TLR4）组、缺硒+干扰TLR4（L+siChTLR4）组,低硒处理5 d后,检测细胞活力、细胞凋亡情况、TLR4信号转导通路与细胞凋亡相关因子的表达。结果显示：1）与C组相比,L组皮质髓质的淋巴细胞数量减少、细胞排列紊乱、皮质髓质充血、核碎裂,广泛的局灶性坏死。L组鸡胸腺组织淋巴细胞间出现裂隙,体积缩小,细胞碎裂,核染色质边集,线粒体肿胀,嵴断裂。2）与15日龄C组相比,L组鸡胸腺中TLR4、MyD88、NF-κB、Caspase-3、Caspase-9、Bax mRNA和蛋白表达水平在15~55日龄中均显著上调,Bcl-2 mRNA和蛋白表达水平呈相反趋势。3）与C组相比,L组MSB1细胞活力显著下降、细胞凋亡数量明显增加、TLR4、MyD88、NF-κB、Caspase-3、Caspase-9、Bax mRNA和蛋白的表达均显著增加、Bcl-2 mRNA和蛋白表达水平极显著降低;与L组相比,L+siChTLR4组细胞活力明显增强、细胞凋亡数量明显减少、相关因子mRNA和蛋白表达显著下降,而L+pCMV-HA-TLR4组细胞活力明显降低、细胞凋亡数量明显增加、相关因子mRNA和蛋白表达均明显增加。综上所述,硒缺乏通过TLR4/MyD88/NF-κB信号通路介导鸡胸腺细胞凋亡,并进一步诱导鸡胸腺损伤。     

酮病奶牛血清中NO含量及NOS活性变化的研究

为了深入研究酮病的发生机理,选择荷斯坦奶牛作实验动物,应用酮粉法和改良式水杨醛比色法随机检测分组,Ⅰ组为10头阳性牛、Ⅱ组为10头对照牛。应用硝酸还原酶法测定血清中一氧化氮(NO)含量和一氧化氮合酶(NOS)活性。实验结果表明对照组奶牛血清中的NO含量及NOS活性均显著大于阳性组。由此可知,酮病可导致奶牛血清中NO含量降低、NOS活性下降。     

酮病奶牛血清中NO含量及NOS活性变化的研究

为了深入研究酮病的发生机理，选择荷斯坦奶牛作实验动物，应用酮粉法和改良式水杨醛比色法随机检测分组，Ⅰ组为10头阳性牛、Ⅱ组为10头对照牛。应用硝酸还原酶法测定血清中一氧化氮(NO)含量和一氧化氮合酶(NOS)活性。实验结果表明对照组奶牛血清中的NO含量及NOS活性均显著大于阳性组。由此可知，酮病可导致奶牛血清中NO含量降低、NOS活性下降。     

硒对氟中毒鸡肝肾GSH-Px活性及其mRNA表达的影响

为探讨硒对氟中毒鸡肝肾组织GSH-Px活性及其mRNA表达的影响,选取180只7日龄海兰褐蛋鸡,随机分为3组,每组60只.Ⅰ组:正常对照组,饲喂全价日粮;Ⅱ组:氟中毒组,在正常日粮中添加氟化钠(NaF),使日粮中氟含量为1 000mg/kg日粮;Ⅲ组:加硒组,在氟中毒组日粮基础上添加亚硒酸钠(Na<,2>SeO<,3>),使日粮中硒含量为4mg/kg日粮.试验期为90d,每隔30d采样,进行肝脏和肾脏谷胱甘肽过氧化物酶(GSH-Px)活性的检测以及GSH-Px mRNA转录水平的测定.结果表明加硒组肝脏和肾脏GSH-Px活性和GSH-Px mRNA转录水平在各时间点均高于氟中毒组(P<0.05).说明日粮中加硒可在一定程度上颉颃氟所致鸡肝肾组织脂质过氧化作用.     

Similar pattern of iNOS expression, NO production and cytokine response in genetic and vaccination-acquired resistance to Marek's disease

NO is produced by macrophages through activation of the inducible enzyme NOS and its production is triggered as an antiviral and antitumoral immune mechanism. Replication of Marek's disease herpes virus (MDV) is inhibited by NO in vitro. MDV induces T-lymphomas in the chicken and a genetic resistance to tumor development has been linked to the B21 major histocompatibility complex. During the first initial week of viral replication after inoculation of the highly virulent RB-1B MDV strain, histocompatible B21/B21 chickens developed strong iNOS expression and NO production capacity in the spleen, in parallel with strong systemic NO production in the serum. Comparable NO response was not seen with the vaccinal strain HVT. In contrast, reduction in spleen macrophage number and delay in iNOS gene expression was observed in genetically susceptible B13/B13 chickens after MDV infection, in addition to suppression of IFN-gamma-inducible NO production. However, vaccination with HVT 3 days before RB-1B inoculation restored strong iNOS gene expression in the spleen 1 week later and inducible NO production 3 weeks later. Following the pattern of iNOS gene expression, early strong expression of cytokines with powerful iNOS-inducing activity such as IFN-gamma and CC chemokines from the MIP family (MIP-1beta, K203) was observed in genetic resistance and resistance acquired after vaccination with HVT. In conclusion, resistance to MDV appeared preferentially linked in both types of resistance to the early establishment of cytokine induction characteristic of a Th1 immune response, thus favoring the development of an early and strong NO response.     

Effects of Compound Chinese Herbal Medicinal Polysaccharides on Immune Signal Molecules Expression in Different MHC B-LβⅡ Genotypes Chickens Lymphocyte

This study was aimed to explore the effect of compound Chinese herbal medicinal polysaccharides (cCHMPS) on immunomodulatory in different MHC B-LβⅡ genotype chickens.MHC B-LβⅡ genotype was analyzed by PCR-SSCP method in 500 chickens.Collected the blood from different MHC B-LβⅡ genotype chickens,isolated peripheral blood lymphocytes,and added cCHMPS with the final concentration of 200,100,75,50,25 and 0 μg/mL cocultured for 24 h.Then the lymphocyte supernatant cAMP,cGMP,Ca²⁺,NO and iNOS content were detected by ELISA.The results showed that cCHMPS could increase cAMP,cGMP,Ca²⁺,NO and iNOS levels in chicken lymphocyte supernatant compared with control group in each MHC B-LβⅡ genotype chickens.And when the concentration of cCHMPS was 50 μg/mL,cAMP,Ca²⁺,NO and iNOS levels of AA and BC genotypes chicken lymphocyte supernatant were higher than that of the same genotype chicken,cGMP level of BC genotype chicken lymphocyte supernatant was higher than that of the same genotype chicken;When cCHMPS concentration was 75 μg/mL,cGMP level of AA genotype chicken lymphocyte supernatant was higher than that of the same genotype chicken;When cCHMPS concentration was 100 μg/mL,cAMP,cGMP,Ca²⁺,NO and iNOS levels of BB genotype chicken lymphocyte of the supernatant were higher than that of the same genotype chicken.cCHMPS could increase cAMP,cGMP,Ca²⁺,NO and iNOS levels in different MHC B-LβⅡ genotypes chickens,and the cCHMPS optimum immunomodulatory doses were different in each MHC B-LβⅡ genotypes chickens.     

Impact of fresh or used litter on the posthatch immune system of commercial broilers

This study was carried out to investigate the effects of exposure of growing broiler chickens of commercial origin to used poultry litter on intestinal and systemic immune responses. The litter types evaluated were fresh wood shavings or used litter obtained from commercial poultry farms with or without a history of gangrenous dermatitis (GD). Immune parameters measured were serum nitric oxide (NO) levels, serum antibody titers against Eimeria or Clostridium perfringens, mitogen-induced spleen cell proliferation, and intestinal intraepithelial lymphocyte or splenic lymphocyte subpopulations. At 43 days posthatch, birds raised on used litter from a GD farm had higher serum NO levels and greater Eimeria or C. perfringens antibody levels compared with chickens raised on fresh litter or used, non-GD litter. Birds raised on non-GD and GD used litter had greater spleen cell mitogenic responses compared with chickens raised on fresh litter. Finally, spleen and intestinal lymphocyte subpopulations were increased or decreased depending on the litter type and the surface marker analyzed. Although it is likely that the presence of Eimeria oocysts and endemic viruses varies qualitatively and quantitatively between flocks and, by extension, varies between different used litter types, we believe that these data provide evidence that exposure of growing chicks to used poultry litter stimulates humoral and cell-mediated immune responses, presumably due to contact with contaminating enteric pathogens.     

柔嫩艾美耳球虫感染鸡盲肠和脾脏一氧化氮合酶的表达

采用NADPH—d(nicotinamide adenine dinucleotide phosphate—diaphroase)组织化学法观察了雏鸡感染柔嫩艾美耳珠虫(E．tenella)后一氧化氮合酶(N0S)在盲肠和脾脏中的分布与表达情况。试验结果表明，所有正常鸡盲肠粘膜下层和肌层均有较深的着色，根据以往的资料和N0S的表达特性初步判断为神经元型N0S(nNOS)；试验鸡在感染后3～5d，盲肠粘膜上皮和肠腺上皮也有较深的着色，并从感染后7d开始着色减弱；而对照组鸡盲肠粘膜上皮和肠腺上皮以及对照组和试验组的脾脏几乎不着色或着色很浅。试验结果提示，盲肠粘膜上皮和肠腺上皮的着色可能是诱导型N0S(iN0S)表达的结果，而由其产生的N0参与雏鸡球虫感染过程。     

感染传染性支气管炎病毒后雏鸡血液中一氧化氮合酶和一氧化氮的动态观察

80只14日龄SPF鸡随机均分为实验组和对照组，实验组用鸡传染性支气管炎病毒M41株人工感染，感染后1、3、5、7、11、15天分别测定感染组及对照组血清中一氧化氮合酶(NOS)和一氧化氮(NO)的含量，研究NO在鸡传染性支气管炎发病过程中的作用。结果表明：实验组血清NOS含量自攻毒后第3天上升，一直持续至鸡群恢复期，但与对照组无显著差异。实验组血清NO含量在攻毒后第3天也开始上升，攻毒后第5、7、11天血清NO含量显著高于对照组，此后血清中NO含量上升趋势有所减缓。提示NO可能参与调节了传染性支气管炎的发生发展过程。     

Serum glutathione peroxidase activity and blood selenium in pigs

Blood serum glutathione peroxidase activity and blood selenium concentration were measured in blood samples from pigs subjected to experimentally induced selenium deficiency and dietary selenium supplementation on graded levels. A highly significant correlation between blood selenium and serum GSH-Px activity in pigs, especially in selenium deficient pigs, was demonstrated. There was also a strong relationship between blood selenium concentration and serum GSH-Px activity in pigs receiving dietary selenium at graded levels. Serum GSH-Px activity exhibited an excellent close-response relationship to dietary selenium. Linear regression analysis showed that the increased serum GSH-Px activity was a function of the dietary selenium concentration. The fitness of serum in monitoring slight changes of the selenium status of pigs with help of the estimation of GSH-Px activity was discussed. The measurement of serum GSH-Px activity seems to provide a useful and rapid means for defining selenium requirements and for identifying selenium deficiency in growing pigs.     

The effects of soybean selenium proteinate on tissue selenium and meat quality traits in finishing pigs

The purpose of the present study was to evaluate the effects of soybean selenium proteinate on Se tissue retention and meat quality in pigs. In group A (n = 11) the mixtures were supplemented with soybean selenium proteinate, in group B (n = 11) with sodium selenite and in group C (n = 11) with Se-enriched yeast (0.3 mg Se per kg in all groups). The use of soybean selenium proteinate resulted in lower retention of Se in tissues (liver, heart, muscle) compared to Se-enriched yeast. Selenium concentrations in tissues achieved by soybean selenium proteinate and sodium selenite were comparable. No differences in serum Se, serum GSH-Px and meat quality traits were found among the groups.     

猪圆环病毒2型对体外培养的仔猪淋巴细胞抗氧化能力的影响

为进一步了解猪圆环病毒2型(PCV-2)引起淋巴细胞凋亡的机理,测定了PCV-2对体外培养的仔猪淋巴细胞抗氧化能力的影响。取培养后0,2,6,24,48 h的上清液和细胞,用试剂盒测定上清液中总抗氧化能力、一氧化氮(NO)含量、超氧阴离子自由基活性和超氧化物岐化酶活力的变化,同时测定淋巴细胞内一氧化氮合酶(NOS)活力。结果表明,试验组与对照组总抗氧化能力无显著性差异(P>0.05);试验组抗超氧阴离子自由基活性与对照组相比,除了0 h,其他时间点试验组均显著高于对照组(P<0.05);总超氧化物岐化酶活力试验组和对照组均维持在19 U/mL左右,无显著差异(P>0.05);NO含量除24 h时试验组高于对照组外(P<0.05),其余时间两组间差异不显著;细胞内NOS活力除0 h外,其余时间均是对照组高于试验组,且2、24 h显著增高(P<0.05);对照组诱导型一氧化氮合酶(iNOS)活力6 h时显著高于试验组(P<0.05),其余时间(0 h除外)也较试验组高。