L-精氨酸对肺动脉高压肉鸡肺小动脉平滑肌细胞凋亡的影响

将240羽14日龄艾维茵-2000商品代肉鸡于14d时随机等分为常温对照组（NT组），低温组（LT组）和低温加L-精氨酸组（LA），白14d起，LT和LA组舍内温度从28℃以1～2℃／d的速度下降，至21d降至12～14℃，并维持到试验结束。此外，LA组自14d起在饲料中按100mg／kg剂量添加L—Arg，直至试验结束。记录肺动脉高压综合征（PHS）发病率，并分别于24、32、39和45d测定右心室／全心室质量比（RV／TV）、血浆NO、肺小动脉管壁面积／管总面积（WA／TA）和平均中膜厚度（mMTPA），并用原位缺口末端标记法（TUNEL法）对肺小动脉凋亡平滑肌细胞进行染色和计数。结果：LT组肉鸡PHS发病率、RV／TV、mMTPA和WA／TA值较NT组升高（P〈0．05）；LA组肉鸡PHS发病率较LT组降低（P〈0．05），mMTPA和WA／TA值与LT组相比呈下降趋势，在32d时显著降低（P〈0．05）；LT组血浆N0浓度总体上与NT组差异不显著（P〉0．05），仅在39d时降低（P〈0．05），而LA组血浆N0浓度自32d时起较NT和LT组显著升高（P〈0．05）；LA组肉鸡肺小动脉平滑肌凋亡细胞百分率较NT组和LT组均显著升高（P〈0.05），但LT组与NT组之间相比无显著差异（P〉0．05）。上述结果表明，L-Arg／NO通过促进肺小动脉平滑肌细胞凋亡，从而在一定程度上抑制了肺血管重构的形成。     

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。     

红三叶异黄酮对肉鸡血液几种内源性激素水平的影响

本试验旨在研究饲粮中添加红三叶异黄酮对肉鸡血液几种内源性激素水平的影响。选取1日龄雄性爱拔益加肉仔鸡240羽,随机分为4组(每组4个重复,每个重复15只),分别饲喂在基础饲粮中添加0(对照组)、10(试验Ⅰ组)、20(试验Ⅱ组)、30 mg/kg(试验Ⅲ组)红三叶异黄酮的试验饲粮。试验持续7周。结果表明:试验Ⅰ组和试验Ⅱ组的平均日增重显著或极显著高于对照组和试验Ⅲ组(P<0.05或P<0.01)。各试验组料重比均低于对照组,但差异不显著(P>0.05)。血清生长激素(GH)水平,试验Ⅱ组在21、35和49日龄均显著或极显著高于对照组(P<0.05或P<0.01),试验Ⅰ组在49日龄、试验Ⅲ组在21日龄显著或极显著高于对照组(P<0.05或P<0.01);血清类胰岛素生长因子Ⅰ(IGF-Ⅰ)水平,各试验组在21日龄均显著高于对照组(P<0.05),试验Ⅱ组在49日龄显著高于对照组和其他试验组(P<0.05);血清三碘甲腺原氨酸(T3)水平,试验Ⅰ组在35和49日龄、试验Ⅱ组在49日龄均显著或极显著高于对照组(P<0.05或P<0.01);血清四碘甲腺原氨酸(T4)水平,试验Ⅰ组和试验Ⅲ组在35日龄显著低于对照组(P<0.05);血清T3/T4,各试验组在21、35和49日龄均高于对照组,并且在35和49日龄试验Ⅰ组与对照组达到显著水平(P<0.05);血清睾酮(TESTO)水平,各组在21、35和49日龄均无显著差异(P>0.05)。由此得出,红三叶异黄酮可通过调节体内GH、IGF-Ⅰ、T3和T4水平来影响肉鸡的生长性能,饲粮中添加20 mg/kg时促生长效果较好。     

基因型对红三叶异黄酮含量的影响

采用高效液相色谱法,对4个不同红三叶品种的异黄酮含量进行了分析,发现基因型对红三叶的异黄酮总含量影响显著,4个供试材料的异黄酮总含量为:新品系R-1>瑞德>岷山>多丽.基因型对红三叶各异黄酮单体含量变化影响不同,对大豆黄素含量的变化影响最大,对刺芒柄花素含量的变化影响最小.红三叶积累刺芒柄花素的能力最高,其次是鹰嘴豆芽...     

一氧化氮对肉鸡肺血管重塑影响的研究进展

肺血管重塑是肉鸡肺动脉高压综合征的重要病理学变化特征,虽然对其形成的机制尚未完全清楚,但众多细胞因子在其形成过程中起重要作用已得到共识。一氧化氮作为一种信号物质,在血管扩张、细胞增殖与凋亡、内皮素分泌与合成以及抗氧化等过程中发挥着重要的调控作用,显示了其在抑制肉鸡肺血管重塑、预防和治疗肺动脉高压发生方面有着广阔的应用前景。     

缺氧性肺动脉高压肺血管重构的细胞生物学研究进展

肺血管重构在肺动脉高压的形成、发展和维持中起重要作用。血管壁细胞的增殖和肥厚是造成血管重构的病理基础。因此 ,了解缺氧条件下肺血管 (尤其是肺动脉 )壁细胞的代谢、分化、增殖、凋亡及其分泌的生物活性物质的变化规律 ,了解抑制血管重构的方法 ,对探索肺血管重构的机制以及缺氧性肺动脉高压的防治具有重要的理论和实践意义     

肺动脉高压肉鸡肺小动脉中膜5-HT量及其与肺血管重构的关系

静脉注射纤维素粒子复制肉鸡肺动脉高压模型,观察肺小动脉中膜5-羟色胺(5-HT)表达和肺小动脉管壁病理形态学变化,探讨5-HT与肺血管重构的关系。80羽科宝肉鸡分为对照组(n=30)和试验组(n=50)。20日龄时,试验组每羽鸡静脉注射0.3 mL的纤维素悬液;对照组每羽鸡静脉注射等体积生理盐水。记录肺动脉高压综合征(PHS)发病率,并分别于21、28、35、42 d从各组随机抽样,测定右心室/全心室质量比(RV/TV)、红细胞压积(PCV)、血红蛋白(Hb)、肺小动脉管壁面积/管总面积(WA/TA)、平均中膜厚度(mMTPA)和肺厚壁末梢血管百分比(TWPV%);采用免疫组化方法标记5-HT,并用病理图像分析软件检测肺小动脉5-HT的量。结果表明:试验组肉鸡PHS发病率显著高于对照组(P<0.05);RV/TV值在35、42 d时显著升高(P<0.05);PCV在28、35 d时显著升高(P<0.05);Hb值在35 d时显著升高(P<0.05);血管mMTPA、WA/TA和TWPV%在35、42 d时均显著升高(P<0.05);肺小动脉5-HT含量升高,在各时间点均差异显著(P<0.05),且5-HT含量...     

红三叶异黄酮的提取方法和生理功能

红三叶异黄酮(RCI)作为一类植物雌激素,主要存在于豆科植物红三叶草中。其主要成分为芒柄花素、鹰嘴豆芽素A、染料木素和大豆素,具有弱雌激素作用,且具有抗氧化、抗肿瘤、抗病毒以及改善骨质疏松和妇女更年期综合症等作用。近年来RCI在畜牧业生产中开始被应用,有望被开发为安全有效的绿色饲料添加剂。本文综述了RCI的结构特征、提取纯化鉴定方法、生理功能及其对畜禽生长、免疫、繁殖及骨骼发育的影响及相关作用机制。     

低温诱发肉鸡肺动脉高压中肺血管重塑的作用

采用低温处理肉仔鸡的方法,通过测定肺动脉压、肺小动脉中膜厚度占外径百分比及中膜面积与血管总面积比的变化,探讨肉鸡肺动脉高压的发生机制.结果表明:肺血管重塑在低温诱发肉鸡的肺动脉高压发生发展中起重要作用.     

Trifolium pratense isoflavones improve pulmonary vascular remodelling in broiler chickens

Pulmonary arterial remodelling is a pathological characteristic of pulmonary arterial hypertension (PAH), which contributes to the development of sustained pulmonary hypertension. The aim of this study was to investigate the effects of dietary Trifolium pratense isoflavones on pulmonary vascular remodelling in experimental broiler pulmonary hypertension syndrome. Exposure to sub‐thermoneutral environmental temperatures increased broiler's pulmonary hypertension syndrome incidence and raised expression levels of nitric oxide, endothelin and endothelial nitric oxide synthase. Dietary supplementation (20 mg/kg basal diet) with Trifolium pratense isoflavones reduced pulmonary hypertension syndrome incidence and improved pulmonary vascular remodelling without affecting growth performance. The beneficial effect likely came from isoflavone improved pulmonary vascular remodelling. Isoflavone induced inducible nitric oxide synthase expression, which led to increased nitric oxide level. The nitric oxide could mediate vasorelaxation in the lungs. At the same time, the expression of endothelin was downregulated by isoflavone. Dietary supplementation of Trifolium pratense isoflavone might be a potential therapeutic strategy for the treatment of pulmonary hypertension.     

L-Arginine inhibiting pulmonary vascular remodelling is associated with promotion of apoptosis in pulmonary arterioles smooth muscle cells in broilers

Objective

Pulmonary vascular remodelling is one of the important pathological bases of broiler pulmonary hypertension syndrome (PHS). Nitric oxide (NO) has been found to inhibit proliferation and to induce apoptosis in pulmonary artery smooth muscle cells (SMC) in mammals with pulmonary hypertension. The present study was conducted to evaluate the effects of NO precursor l-arginine on pulmonary vascular remodelling in broilers with pulmonary hypertension induced by cold exposure and to examine whether NO-induced apoptosis in pulmonary arteriole SMC is involved in the regulatory mechanisms.

Methods

Two hundred and forty mixed-sex commercial broilers were equally assigned to three groups and reared in normal brooding temperatures before day 14. Starting on day 14 continuing until the end of the experiment, the control group was brooded in normal temperatures whereas the other two groups were subjected to low ambient temperatures with or without l-arginine added to the basal diets. Cumulative PHS mortality and body weight were recorded in each group. Right/total ventricle ratio (RV/TV), plasma NO concentration and pulmonary vascular morphological changes were analyzed. TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay was used to detect apoptosis in pulmonary arteriole SMC.

Result

l-Arginine, in group A, had no effect on body weights under cold temperature condition. Birds kept in group B had increased PHS mortality, RV/TV ratio, vessel wall area/vessel total area ratios (WA/TA) and mean media thickness in pulmonary arterioles (mMTPA) (P < 0.05). Percentages of apoptotic SMC in pulmonary arterioles in group B were not altered by cold exposure (P > 0.05). Supplemental dietary l-arginine in group A elevated plasma NO level (P < 0.05), reduced PHS mortality (P < 0.05), attenuated pulmonary vascular remodelling and increased the percentages of apoptotic SMC (P < 0.05) when compared with the group B.

Conclusion

Supplemental l-arginine partially inhibited pulmonary vascular remodelling that occurred secondary to increased pulmonary pressure; NO-induced apoptosis in arteriole SMC might contribute to its regulatory effect on pulmonary vascular structural changes.     

红三叶愈伤组织培养与异黄酮的产生

对红三叶Trifolium pratense下胚轴和子叶进行愈伤组织的培养,结果表明:添加2.0 mg/L 2,4-D和0.5 mg/L 6-BA的MS培养基最适合诱导愈伤组织。采用紫外分光光度法对愈伤组织总异黄酮含量进行测定,结果发现:愈伤组织中异黄酮的含量明显高于实生苗,子叶愈伤组织中异黄酮的含量比下胚轴愈伤组织中的高,且差异显著(P<0.05)。     

红三叶不同外植体与愈伤组织类型对愈伤组织内异黄酮含量的影响

以红三叶真叶、子叶、上胚轴和下胚轴为外植体诱导愈伤组织,根据愈伤组织形态分为A型、B型和C型,采用紫外分光光度法测定不同外植体来源和类型的愈伤组织内异黄酮含量。试验结果表明:初代培养中,来自真叶的愈伤组织异黄酮含量最高(1.562μg/mL),其次是子叶(0.904μg/mL)和下胚轴(0.885μg/mL),上胚轴的最低(0.774μg/mL);继代培养1次后,上胚轴的含量升高(0.941μg/mL),真叶,子叶和下胚轴的含量均下降;3种愈伤组织类型,均以B型的异黄酮含量为最高,其次为A型,C型的含量最低。     

l-Arginine inhibiting pulmonary vascular remodelling is associated with promotion of apoptosis in pulmonary arterioles smooth muscle cells in broilers

OBJECTIVE: Pulmonary vascular remodelling is one of the important pathological bases of broiler pulmonary hypertension syndrome (PHS). Nitric oxide (NO) has been found to inhibit proliferation and to induce apoptosis in pulmonary artery smooth muscle cells (SMC) in mammals with pulmonary hypertension. The present study was conducted to evaluate the effects of NO precursor l-arginine on pulmonary vascular remodelling in broilers with pulmonary hypertension induced by cold exposure and to examine whether NO-induced apoptosis in pulmonary arteriole SMC is involved in the regulatory mechanisms. METHODS: Two hundred and forty mixed-sex commercial broilers were equally assigned to three groups and reared in normal brooding temperatures before day 14. Starting on day 14 continuing until the end of the experiment, the control group was brooded in normal temperatures whereas the other two groups were subjected to low ambient temperatures with or without l-arginine added to the basal diets. Cumulative PHS mortality and body weight were recorded in each group. Right/total ventricle ratio (RV/TV), plasma NO concentration and pulmonary vascular morphological changes were analyzed. TdT-mediated dUTP-biotin nick-end labeling (TUNEL) assay was used to detect apoptosis in pulmonary arteriole SMC. RESULT: l-Arginine, in group A, had no effect on body weights under cold temperature condition. Birds kept in group B had increased PHS mortality, RV/TV ratio, vessel wall area/vessel total area ratios (WA/TA) and mean media thickness in pulmonary arterioles (mMTPA) (P<0.05). Percentages of apoptotic SMC in pulmonary arterioles in group B were not altered by cold exposure (P>0.05). Supplemental dietary l-arginine in group A elevated plasma NO level (P<0.05), reduced PHS mortality (P<0.05), attenuated pulmonary vascular remodelling and increased the percentages of apoptotic SMC (P<0.05) when compared with the group B. CONCLUSION: Supplemental l-arginine partially inhibited pulmonary vascular remodelling that occurred secondary to increased pulmonary pressure; NO-induced apoptosis in arteriole SMC might contribute to its regulatory effect on pulmonary vascular structural changes.     

岷山红三叶总异黄酮提取方法的研究

为选择提取岷山红三叶中总异黄酮的最佳方法,本文研究了用回流法、冷浸法和索式提取法提取岷山红三叶中总异黄酮的效果.通过紫外分光光度法测定提取液中的总黄酮含量,结果表明:回流提取法提取效果优于冷浸法和索式提取法.具有安全、简便和提取率高的优点.     

维拉帕米对环境低温诱发肉鸡肺动脉平滑肌细胞增殖的作用

环境低温诱发肉鸡腹水综合征(AS)发生过程中,肺血管发生明显重塑,并以肺动脉中膜增厚为主要特征。血管平滑肌细胞的数量将影响血管中膜的厚度[1]。故推测认为肉鸡肺动脉平滑肌细胞增殖在肺血管重塑过程中起着重要作用。研究认为细胞内的Ca2 是重要的细胞内第二信使,在细胞增殖过程中起着重要的作用。维拉帕米作为一种钙通道阻滞剂,可抑制Ca2 内流,使细胞内Ca2 水平降低,对肉鸡AS的发生有明显的预防作用[2]。但有关维拉帕米对环境低温诱发肉鸡AS过程中肺动脉血管平滑肌细胞增殖的作用,未见报道。增殖细胞核抗原(proliferating cell nucle…     

氟西汀和5-羟色胺对肉鸡肺动脉平滑肌细胞增殖与凋亡的影响

为探讨5-羟色胺转载体(5-HTT)在肉鸡肺动脉高压综合征发病中的机制,采用MTT比色法、流式细胞术及Hoechst33258荧光染色法研究5-羟色胺(5-HT)和5-HTT抑制剂氟西汀对体外培养的肉鸡肺动脉平滑肌细胞(PASMC)增殖与凋亡的影响,发现氟西汀能够抑制5-HT促PASMC增殖的作用;氟西汀能明显促进PASMC的凋亡,但氟西汀和5-HT共同作用于细胞,PASMC凋亡率明显少于氟西汀单独处理组。表明5-HTT在调节肉鸡PASMC的增殖和凋亡方面起重要作用,有可能参与肺动脉高压肉鸡肺血管重构的形成。     

低温诱发肉鸡腹水综合征发生过程中肺血管重塑与肺动脉高压的关系

将160只15日龄雄性AA商品代肉鸡随机分为对照组((22±1.5)℃)和低温组((11±2)℃)。15~50日龄,每组每周随机取6只,以右心导管法直接测定肺动脉压(PAP),并取肺组织做石蜡切片进行Weigert-间苯二酚复红染色,分析肺血管重塑情况。50日龄时统计整个饲养过程中肉鸡腹水综合征(AS)发生率。结果显示,低温组肉鸡AS发生率(18.75%)极显著高于对照组(1.25%)(P<0.01);低温组肉鸡PAP从22日龄开始较对照组明显升高(P<0.01或P<0.05);20~50、50~100、100~200μm肺动脉结构分别从36、43、43日龄开始较对照组发生了明显的重塑(P<0.01或P<0.05)。结果表明,低温诱发肉鸡AS过程中出现了明显的PAP升高和肺血管重塑,且肺动脉高压(PH)促进了肺血管重塑,肺血管重塑加剧了PAP升高。     

Proliferation of pulmonary artery smooth muscle cells in the development of ascites syndrome in broilers induced by low ambient temperature

Pulmonary vascular remodelling, mainly characterized by arterial medial thickening, is an important pathological feature of broiler ascites syndrome (AS). Since vascular smooth muscle cells (VSMC) form the major cellular component of arterial medial layer, we speculate that VSMC proliferation is one of the causes of pulmonary arterial medial thickening in ascitic broilers. Hence, the present study was designed to investigate the role of VSMC proliferation in pulmonary vascular remodelling in development of AS induced by low ambient temperature. Broilers in control group (22 +/- 1.5 degrees C) and low temperature group (11 +/- 2 degrees C) were sampled every week at 15-50 days of age. Proliferative indexes of VSMC in pulmonary arteries were assessed with proliferating cell nuclear antigen, and the relative medial thickness (RMT) and relative wall area (RWA), as indexes of pulmonary vascular remodelling, were examined by computer-image analysing system. The results showed that the high incidence (18.75%) of AS was induced by low temperature, and a significantly increased VSMC proliferation was observed in pulmonary arteries in the low temperature group at 22-50 days of age (P < 0.05). In addition, RMT and RWA in pulmonary arteries were significantly elevated in the low temperature group from 36 days of age (P < 0.05), indicating that pulmonary vascular remodelling occurred following VSMC proliferation in AS. Our data suggest that proliferation of VSMC may facilitate pulmonary vascular remodelling and have a pivotal role in AS induced by low ambient temperature.