肉鸡腹水综合征患鸡右心组织钙沉积和Ca2+-ATPase活性变化

右心肥大衰竭是腹水综合征患鸡发病的重要环节之一,而心肌细胞内Ca^2＋浓度在调节心脏收缩和舒张功能及其生长方面都起着重要作用。本试验应用右心导管法测定AS患鸡右心压力变化情况,采用焦锑酸钾沉淀法、电镜酶细胞化学法研究AS患鸡右心组织Ca^2＋和钙泵（Ca^2＋-ATPase）活性变化及其精确定位。结果显示AS组肉鸡右心室舒张压极显著高于对照组（P〈0.01）,同时,右心室内压最大变化速率也极显著降低（P〈0.01）;对照组肉鸡右心组织偶见少量散在的Ca^2＋沉淀颗粒,低温诱发AS患鸡右心组织发生了明显的钙沉积;对照组肉鸡的右心组织Ca^2＋-ATPase以高电子密度颗粒分布于肌浆网、线粒体膜等处,AS患鸡心脏组织的Ca^2＋-ATPase的电子密度颗粒显著减少或缺失。本研究揭示,在低温条件下AS患鸡具有明显的右心舒张功能障碍,Ca^2＋浓度增高和Ca^2＋-ATPase功能抑制可能在其中起着重要作用。     

肉鸡血清肌钙蛋白T与腹水综合征的关系研究

本试验建立了肉鸡血清中心源性肌钙蛋白T(Tn-T)的ELISA测定方法,用于对肉鸡腹水综合征的早期非损伤性诊断指标.结果表明,患腹水综合征肉鸡的血清Tn-T平均测定值为0.242±0.0703 ng/ml,而正常鸡的平均值为0.1 79±0.0467 ng/ml;以血清肌钙蛋白T测定值大于等于0.2 ng/ml作为判定肉鸡腹水综合征的标准,判别准确性达到78%.检测血液中肌钙蛋白T是诊断幼龄鸡早期心脏病的重要方法,可作为一种非损伤性方法用于针对肉鸡腹水综合征的育种方案中.     

缺氧与肉鸡心肌细胞c-fos和c-myc基因表达的关系

利用细胞培养、原位杂交、免疫组化、图像分析等技术研究缺氧与肉鸡心肌细胞癌基因c-fos和c-myc表达的关系,进一步阐明缺氧与以右心肥大、衰竭为特征的肉鸡腹水综合征的关系。结果显示,缺氧显著引起心肌细胞内癌基因c-fos和c-mycmRNA的表达(c-fos mRNA:常氧149.6±22.4;缺氧205.4±57.6,P<0.01;c-myc mRNA:常氧155.2±25.7;缺氧197.4±26.2,P<0.01)。缺氧显著引起心肌细胞内癌基因c-fos和c-myc蛋白的表达(c-fos蛋白:常氧159.1±37.1,缺氧240.3±49.6;c-myc蛋白:常氧149.6±24.9,缺氧236.3±55.4;P<0.01)。结果表明缺氧显著诱发肉鸡心肌细胞内癌基因c-fos、c-myc的转录和表达,是启动心肌细胞肥大的重要原因。因此本研究进一步阐明缺氧是以右心肥大衰竭为特征的肉鸡腹水综合征的主要诱因。     

维拉帕米对低温诱发腹水综合征肉鸡右心功能的影响

本试验旨在探讨钙离子内流阻滞剂维拉帕米（verapamile）对腹水综合征肉鸡右心功能的影响。结果显示，维拉帕米使低温诱发的肉鸡腹水症发生率以及肉鸡腹水心脏指数降低。与低温对照组相比，维拉帕米组28日龄鸡右心室收缩压显著降低（P〈0．05），36、44日龄鸡右心室收缩压有所降低（P〉0．05），而28和36日龄鸡右心室舒张压显著降低（P〈0．01）。     

早期限饲对在常温和寒冷环境中的肉鸡生理反应、生产性能和腹水综合征发生率的影响

现代选育技术一方面选育出快速生长和高饲料效率的肉鸡,另一方面也加剧了肉鸡对腹水综合征等代谢紊乱症的易感性。腹水综合征是肉鸡死亡和肉鸡工业经济损失的主要原因。寒冷环境是腹水综合征主要触发因素,而早期限饲能够显著缓解腹水综合征和死亡的发生。然而,早期限饲、寒冷环境温度以及它们的相互作用对肉鸡生理的相互影响研究很少。为了解决这个问题,320只1日龄肉仔公鸡被分为自由采食组和限饲组两个处理组(每个组8个重复,每个重复20只鸡)。早期限饲组鸡限饲期为7日龄到14日龄。第21天时每个处理组一半的鸡(4个重复)在寒冷环境中饲养,另外一半鸡(4个重复)仍然在常温环境下饲养。在第7、14、21、28、35、42天后测定肉鸡的平均日采食量、平均日增重、和料肉比;第39和46日龄根据每个重复平均重挑选两只鸡进行屠宰并收集血样;然后计算内脏器官相对重量和右心室/总心室比率。结果显示:与常温组相比,寒冷组28-42日龄肉鸡具有更高的平均日采食量和饲料转化效率(P0.05);寒冷组累积的腹水综合症死亡率显著高于常温组(P0.001);寒冷进行限饲组肉鸡与寒冷正常饲喂组的肉鸡的腹水综合征死亡率从8.75%显著降低到1.25%(P0.001);寒冷组肉鸡右心室显著增厚,并且右心室的心脏相对重、血细胞容积和甲状腺浓度显著增高(P0.05),但是进行限饲后,这些参数没有发生显著变化(P0.05)。在冷应激的情况下,早期限饲显著降低了丙氨酸转氨酶和天门冬氨酸转氨酶的活性(P0.05);环境温度和是否限饲对血清甘油三酯、胆固醇、高密度脂蛋白和总蛋白没有显著影响(P0.05)。总之,研究结果表明,限饲通过促进内脏器官更好地发育降低腹水综合征的发生,从而更好地帮助缓解肉鸡代谢过快的压力和缓减损伤。     

右心功能在肉鸡腹水综合征发病过程中的动态变化

20 0只艾维茵商品代肉鸡常规育雏 ,15日龄时随机分为两组 ,10 0只在常规温度下饲养 ( 2 2～ 2 3℃ ) ,为常温组 ;10 0只在低温环境中饲养 ( 9～ 11℃ ) ,为低温组。分别于处理后 0、7、14、2 1d每组随机抽取 10只 ,利用右心导管法测定右心室内压最大变化速率 (±dp/dtmax) (RV) ,并测定腹水心脏指数 (AHI) ,统计至 50日龄出栏时各组腹水发生率。结果为 :( 1)低温处理 1周后 ( 2 2日龄 ) |±dp/dtmax|显著高于 15日龄 (P <0 0 5) ,处理 2周后 ( 2 9日龄 )降至 15日龄水平 ,处理 3周后 ( 36日龄 ) |±dp/dtmax|极显著降低 (P <0 0 1) ,腹水鸡 |±dp/dtmax|较 15日龄极显著下降 (P <0 .0 1) ;常温组 |±dp/dtmax|亦有相近变化趋势。 ( 2 ) 2 9日龄之前AHI变化不显著 ,2 9日龄之后AHI较 15日龄极显著升高 (P <0 .0 1) ,36日龄AHI进一步增加 ,发生腹水鸡AHI达 39 97%± 6 3% ,显著高于15日龄 (P <0 0 1)。常温组AHI变化幅度比低温组小。 ( 3)低温组腹水发生率显著高于常温组 (P<0 .0 5)。结果表明 :反映右心室舒缩功能的±dp/dtmax(RV)出现先升后降变化 ,反映右心肥大程度的AHI逐渐增加 ,证明在肉鸡腹水综合征发生发展过程中右心的功能和结构出现代偿、失代偿直至右心衰竭的动态变化过程。     

维拉帕米对腹水综合征患鸡右心室重塑过程中增殖细胞核抗原变化的影响

右心肥大衰竭是导致腹水综合征(Ascites syndrome,AS)患鸡发病的重要因素。增殖细胞核抗原(Prolifera-ting cell nuclear antigen,PCNA)是细胞周期早期G1和S期的标记物,为同源三聚体,参与DNA的复制和修复。本试验观察了低温诱发AS过程中肉鸡右心组织PCNA表达的动态变化及其维拉帕米对其的影响。结果显示:在29、36、43、50日龄时,与对照组肉鸡相比,低温组肉鸡右心室心肌细胞增殖指数和成纤维细胞增殖指数极显著增高(P0.01);与低温组肉鸡相比,维拉帕米组肉鸡右心室心肌细胞和成纤维细胞增殖指数显著或极显著降低(P0.05或P0.01)。结果表明,环境低温可在一定程度上促进肉鸡右心室心肌细胞和成纤维细胞增殖。维拉帕米可抑制心肌细胞和成纤维细胞过度增殖,从而可能防止右心肥大的发生。     

肉鸡腹水综合征的诊断与治疗

正肉鸡腹水综合征又称雏鸡水肿病、肉鸡腹水症、心衰综合征和鸡高原海拔病,是以病鸡心、肝等实质器官发生病理变化、腹腔积水、右心室肥大扩张、肺淤血水肿、心肺功能衰竭和肝脏显著肿大为特征的综合征,主要发生于幼龄肉用仔鸡。该病与猝死综合症及生长障碍综合症成为当今肉鸡饲养业的3种最严重的疾病,严重影响了肉鸡养殖产业的健康发展。1流行特点肉鸡腹水综合征主要发生于生长速度较快的幼龄鸡群中,多见于3~6周龄,特别是速生型肉鸡,且公     

维拉帕米对低温诱发腹水综合征病鸡右心功能的影响

300只15日龄商品肉仔鸡随机分为常温组、低温组和维拉帕米组，以研究L型电压依赖性钙通道拮抗剂维拉帕米对腹水综合征病鸡右心功能的影响。结果，与低温组相比，维拉帕米可显著降低肉鸡腹水综合征的发生率；维拉帕米组肉鸡腹水心脏指数分别在29、36、43和50日龄时显著或极显著降低；右心室收缩压在36和43日龄时极显著降低，右心室舒张压在36和43日龄时也显著或极显著下降；右心室内压最大变化速率在43日龄时极显著升高。结果表明，维拉帕米可显著降低肉鸡腹水和右心肥大的发生，能有效维护右心功能。     

肢体内外翻畸形肉鸡腿部骨骼矿物元素含量变化及组织学分析

为探究肢体内外翻畸形(valgus-varus deformity, VVD)肉鸡腿部骨骼中矿物元素含量和病理组织学变化情况,为无VVD肉鸡选育提供参考,本试验选用28、38日龄健康和患VVD腿病的哈伯德肉鸡,对其股骨、胫骨、跖骨进行钙、磷及灰分含量的测定。采用乙二胺四乙酸二钠(EDTA)络合滴定法测定钙含量,采用分光光度计法测定磷含量;对38日龄肉鸡胫骨进行铜、锰、锌含量的测定和骨骼切片组织学分析,铜、锰、锌含量通过电感耦合等离子体发射光谱法进行测定。结果显示:与健康鸡相比,28日龄VVD鸡胫骨中磷含量显著降低(P0.05);钙、灰分和铜、锰、锌含量均出现下降趋势;VVD鸡股骨、胫骨、跖骨骨小梁面积和骨细胞数均显著或极显著低于健康鸡(P0.05或P0.01)。研究表明,VVD鸡腿骨中各矿物元素含量均下降,组织学结构发生异常改变。     

Increased calcium deposits and decreased Ca2+-ATPase in right ventricular myocardium of ascitic broiler chickens

Right ventricular hypertrophy and failure is an important step in the development of ascites syndrome (AS) in broiler chickens. Cytoplasmic calcium concentration is a major regulator of cardiac contractile function and various physiological processes in cardiac muscle cells. The purpose of this study was to measure the right ventricular pressure and investigate the precise ultrastructural location of Ca(2+) and Ca(2+)-ATPase in the right ventricular myocardium of chickens with AS induced by low ambient temperature. The results showed that the right ventricular diastolic pressure of ascitic broilers was significantly higher than that of control broilers (P < 0.01), and the maximum change ratio of right intraventricular pressure (RV +/- dp/dt(max)) of ascitic broilers was significantly lower than that of the controls (P < 0.01). Extensively increased calcium deposits were observed in the right ventricular myocardium of ascitic broilers, whereas in the age-matched control broilers, calcium deposits were much less. The Ca(2+)-ATPase reactive products were obviously found on the sarcoplasmic reticulum and mitochondrial membrane of the control right ventricular myocardium, but rarely observed in the ascitic broilers. The data suggest that in ascitic broilers there is the right ventricular diastolic dysfunction, in which the overload of intracellular calcium and the decreased Ca(2+)-ATPase activity might be the important factors.     

中西医结合治疗临床肉鸡腹水症

观察自然腹水症肉鸡的红细胞压积(PCV)、右心/全心比(RV/TV)和A超的变化,同时用中西医结合的方法对肉鸡腹水症进行防治,结果表明,与对照组相比,腹水肉鸡PVC、RV/TV明显升高(P＜0.01),腹水鸡A超检查出现特异增宽的水平波段.用中药和尿酶抑制剂(氢醌)结合的方法对肉鸡腹水症有明显预防和治疗作用.     

Effect of poultry by-product meal on pulmonary hypertension, right ventricular failure and ascites in broiler chickens

We tested the hypothesis that poultry by-product meal would produce a thermogenic response (an increased requirement for oxygen) resulting in an increased incidence of pulmonary hypertension with right ventricular failure and ascites in commercial broiler chickens.

Four treatment groups, each with three replicates of 40 chicks, were fed a commercial broiler starter to day 21, grower to day 35, and the following experimental diets after day 35: group 1, commercial chicken broiler finisher; group 2, commercial chicken broiler finisher with poultry by-product meal added to replace part of the soyabean meal; group 3, commercial chicken broiler finisher with poultry fat added to replace the animal-vegetable (AV) fat; group 4, commercial chicken broiler finisher with both poultry by-product meal and poultry fat added to replace soyabean meal and AV fat. On day 35, pen temperature was reduced to 15°C, and on day 42 to 12°C.

Mortality from ascites between days 35 and 56 was 11(9%) in group 2, 5(4%) in group 4 and 3(2.5%) in groups 1 and 3 The incidence of pulmonary hypertension, as measured by an increased right ventricle: total ventricle (RV:TV) ratio (RV:TV > 0.249) at processing on day 57, was higher in the groups receiving poultry by-product and poultry fat: 27(22.5%) in group 2, 26(21.7%) in group 3, and 20(16.7%) in group 4 compared to that of the controls 12(10%).

     

The effect of dietary l-carnitine supplementation on pulmonary hypertension syndrome mortality in broilers exposed to low temperatures

Oxidative stress is involved in the development of pulmonary hypertension syndrome (PHS) in broilers. l-Carnitine has an antiperoxidative effect and supplemental l-carnitine has been revealed to increase broiler heart weight. The present study was conducted to evaluate the effect of an addition of 100 mg/kg l-carnitine to the basal diets on PHS mortality in cold-exposed broilers. Two-hundred and forty mixed-sex broilers were equally assigned to three groups. The control group was reared in normal temperatures throughout the experiment. Starting on day 14 continuing until the end of the experiment, the other two groups were subjected to a step-down temperature programme (by lowering the temperature 1-2 degrees C per day down to 12-14 degrees C) with or without l-carnitine added to the basal diets. Cold exposure increased the right/total ventricle ratio (RV/TV) and plasma malondialdehyde (MDA), reduced superoxide dismutase (SOD) and led to pulmonary vascular remodelling in birds without feeding additional l-carnitine. Supplemental l-carnitine reduced plasma MDA, increased SOD, inhibited remodelling and postponed the occurrence of PHS for 1 week in cold-exposed broilers; nevertheless, it did not significantly influence the cumulative PHS mortality (p > 0.05). On days 24 and 32, birds fed supplemental l-carnitine had lower RV/TV and higher total ventricle/body weight (p < 0.05) but unchanged right ventricle/body weight ratios (p > 0.05) compared to their cold-exposed counterparts, indicating an increase in left ventricle weight. However, from day 39 on, their RV/TV ratios were suddenly increased (p < 0.05). It was suggested that the l-carnitine-induced increase in left heart weight might partially account for the postponed occurrence of pulmonary hypertension in the early stage by elevating cardiac output, which might, in turn, lead to the resulting increase in pulmonary pressure. In view of its complex effects on cardiopulmonary haemodynamics, l-carnitine supplementation may be impractical for reducing PHS.     

The effect of dietary sodium on right ventricular failure-induced ascites, gain and fat deposition in meat-type chickens.

Experiments were carried out using various levels of sodium (Na+) from NaCl or NaHCO3 to determine: 1) the level of Na+ required to induce ascites alone or in combination with cold temperature and 2) the effect of Na+ on weight gain and fat deposition in broiler chickens. In experiment 1, there were no cases of ascites using levels of Na+, from NaCl at 0.14% to 0.44% in the feed from day 3 or using added Na+, from NaCl at 0.0% to 0.12% in the water from day 3 with a level of 0.14% in the feed. There was no significant difference in 21 or 42 day body weight, feed conversion, or right ventricle:total ventricle (RV:TV) ratio between treatment groups. Day 3 to 4 body weight gains were significantly increased in all treatment groups with added Na+ (p less than 0.01). In experiment 2, with levels of added Na+, from NaCl, at 0.0% to 0.12% in the water with a level of 0.20% in the feed there were two cases of ascites, one at day 7 and one at day 40 at the 0.12% level. There were no significant differences in body weight at days 21 or 42 or in the RV:TV ratios between groups. Feed conversions were improved (p less than 0.01) with the lowest and highest levels of Na+ and a significant increase in day 3 to 4 body weight gain, with increasing Na+ in all treatment groups, was observed.(ABSTRACT TRUNCATED AT 250 WORDS)     

肉鸡腹水症发病机理的研究Ⅲ.低温对肉鸡心功能和心室结构的影响

本研究采用心电图描记技术动态检测低温环境下肉鸡右心功能的变化，同时利用电镜技术观察心肌超微结构的病理变化。研究表明低温处理1周后心电图Ⅱ导联、AVF导联S波幅显著升高，主要呈rS波型;超微结构显示肌原纤维部分断裂、线粒体体积增大为特征；而右 心室病变较轻。低温处理3周、4周后左右心室肌微丝受损, 肌原纤维Z线模糊或消失,线粒体明显肿胀,严重者出现空泡样变，左心室的病理变化比右心室重。研究发现低温处理后肉鸡 右心功能减退，左右心室病理组织学变化有所不同，提示低温处理后肉鸡早期左心主要呈 代偿性变化，中期右心出现代偿功能变化，左心代偿功能增强，而后期左心室出现失代偿的 病变，左心室病变可能对肉鸡腹水症的形成有直接影响。     

N素营养对NaCl胁迫下盐地碱蓬幼苗生长及渗透调节物质变化的影响

通过NaCl和N对盐地碱蓬幼苗生长及渗透调节物质变化的影响研究,结果表明,NaCl和N素对植物的生长的影响是明显的(P<0.05),低NaCl胁迫下N含量的增加对盐地碱蓬幼苗生长的影响不明显,而高NaCl处理下增加营养液中N的含量能明显地缓解盐胁迫,促进盐地碱蓬幼苗的生长.叶片脯氨酸含量随着NaCl浓度和养分N含量的增加而增加,而可溶性糖含量减少. NaCl浓度的增加使得植株总离子含量、Na 含量增加,K 、Ca2 、Mg2 含量减少.随N养分含量的增加,叶中Na 和K 含量增加, Mg2 含量基本上呈减少的趋势.叶片中的Ca2 含量和植株根茎部各离子含量随养分N含量增加的变化规律不明显.     

早期限饲对肉鸡体内脂质过氧化作用和抗氧化酶活性的影响

采用低温诱发肉鸡腹水综合征(AS)，并观察早期限饲对常温和低温饲养时肉鸡AS的发病率、肉鸡体内脂质过氧化作用和抗氧化酶活性的影响。试验1，限饲处理组肉鸡分别于7～14日龄或7～21日龄每天给料8h，对照组肉鸡全程自由采食。试验2，限饲组肉鸡分别于7～14日龄给予对照组肉鸡前一天饲料消耗量的60％或80％，对照组肉鸡自由采食。试验过程中连续测定肉鸡血浆超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH—Px)、丙二醛(MDA)水平和腹水心脏指数(RV／TV值)。结果显示低温显著升高了肉鸡血浆MDA浓度，降低了血浆SOD和GSH—Px的活性；低温饲养肉鸡5～6周龄时的RV／TV值显著升高，AS的发病率显著增加。限饲处理显著降低了肉鸡血浆MDA含量，并且限饲处理肉鸡生长后期血浆中SOD和GSH—Px活性显著高于自由采食组肉鸡。所有的限饲处理均能降低肉鸡AS的发病率，并且早期限饲处理肉鸡42日龄的RV／TV值显著低于非限饲肉鸡。这表明早期限饲能够减轻肉鸡体内脂质过氧化作用，提高机体抗氧化酶的活性，从而降低AS的发病率。     

桑树钙调素蛋白基因MCaM-3的克隆及序列分析与诱导表达

钙调素蛋白(calmodulin CaM)作为真核生物细胞内的多功能Ca2+结合蛋白,在调节植物的生长发育、环境适应性和抗逆性方面具有重要作用。利用桑树表达序列标签(expressed sequence tags,ESTs)克隆了一个编码桑树CaM基因的全长cDNA序列,命名为MCaM-3(GenBank登录号:GQ303247)。序列分析表明,MCaM-3全长951bp,存在143 bp的5′端非翻译序列(5′-UTR)和358 bp的3′端非翻译序列(3′-UTR),其开放读码框(ORF)长450bp,编码149个氨基酸,预测蛋白质分子质量为16.85 kD,等电点为3.95。用在线软件SMART分析显示,MCaM-3蛋白含有4个Ca2+结合基序(EFh)结构域,可以结合Ca2+。同源分析表明,CaM基因在桑树与拟南芥、杨树、大豆、小麦、水稻、玉米各物种间具有很高的保守性。基于桑树和其它19个物种CaM基因的系统进化分析表明,桑树与蓖麻、烟草、大黄、樱桃的亲缘关系较近。半定量RT-PCR检测表明,与正常生长环境相比,MCaM-3基因mRNA的转录水平在低温、干旱、盐胁迫条件下均显著提高,初步推测MCaM-3基因与桑树的抗逆性有一定关联。     

红三叶异黄酮对低温诱发肉鸡腹水综合症发生和抗氧化性能的影响

观察在低温环境下红三叶异黄酮对肉鸡腹水综合症的防治效果及其对肉鸡抗氧化性的影响。300羽肉鸡随机分为3组:常温对照组,低温组、低温黄酮组,采用低温诱发 AS,记录AS发病数,并分别于14,21,28,35和42 d从各组随机抽取6羽肉鸡取样,测定右心肥大指数,红细胞压积,血清和肝脏组织的SOD、MDA和GSH-Px等指标。结果表明环境低温使肉鸡腹水综合症发病率升高,肉鸡日粮添加红三叶异黄酮能够有效地降低寒冷诱发的AS发病率,右心肥大指数和红细胞压积,并提高了抗氧化性能。