敌百虫对大鼠肝细胞[Ca~(2+)]_i、ATP酶及GJIC的影响

通过给大鼠肝细胞培养液中加入敌百虫(染毒终质量浓度分别为0,2,10,50 mg/L),探讨敌百虫对肝细胞内钙离子([Ca2+]i)、Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性及间隙连接通讯(GJIC)的影响。结果显示,不同质量浓度敌百虫作用12 h,[Ca2+]i均极显著高于对照组(P0.01);随着染毒剂量的增加,Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性及GJIC均显著或极显著下降(P0.05或P0.01)。说明敌百虫对肝细胞有明显的毒性作用,GJIC的下调可能与Ca2+浓度的升高和Na+-K+-ATPase、Ca2+-Mg2+-ATPase活性的下降有关。     

磷对成骨细胞活性[ Ca2+]i及细胞周期的影响

在体外培养4 dSD大鼠成骨细胞(OB)的基础上,添加不同浓度磷(0、1、2、4 mmol/L)作用48 h后,观察细胞超微结构,测定钙离子浓度([Ca2+]i);作用36 h后,检测OB细胞周期.磷作用48h后,4 mmol/L磷组OB内线粒体减少,总蛋白含量随磷浓度的增加而减少,4 mmol/L磷组显著低于对照组、1 mmol/L磷组和2 mmol/L磷组(P＜0.05);OB内[Ca2+];浓度在磷各组均增加(P＜0.01),2 mmol/L磷高于1 mmol/L磷(P＜0.05),4 mmol/L磷高于1 mmol/L磷(P＜0.01);磷对细胞周期变化不明显,仅1 mmol/L磷抑制细胞滞留在S期(P＜0.05).表明,添加磷作用48 h后,均促进OB内[Ca2+]i沉积,促进OB的体外矿化,4 mmol/L磷抑制OB的代谢活性,促进OB提前成熟,利于新骨的形成.     

高海拔应激对奶牛血清中K~＋、Na~＋、Ca~（＋＋）、Cl~-、P~（5＋）的影响

[目的]为了有效预防高原应激对奶牛造成的不良反应。[方法]本研究采集从澳洲、天津引进到青海高原10d的奶牛和青海本地奶牛的血液（各15份）,分离出血清,采用BS-400型全自动生化分析仪和MI-921型电解质分析仪测定血清含量。[结果]分析发现,从低海拔地区引进到高海拔地区奶牛血清中Ca＋＋、P5＋、K＋、Na＋、CI-含量明显低于本地奶牛。[结论]说明高海拔应激对引进奶牛机体有一定的影响。     

钙对体外培养大鼠成骨细胞增殖分化及细胞周期的影响

在体外培养大鼠成骨细胞的过程中,添加不同剂量的钙(0、1、2、4 mmol/L),通过检测细胞周期、细胞增殖能力、碱性磷酸酶(ALP)活性及骨桥蛋白表达,探讨了钙对成骨细胞增殖分化及细胞周期的影响.结果表明,2、4 mmol/L钙组在1～8 d均显著或极显著地促进成骨细胞增殖(P<0.05或P<0.01),1 mmol/L钙组则在5、6、8 d有显著或极显著的差异(P<0.05或P<0.01);添加不同浓度的钙除1 mmol/L组第2天外的不同时间均极显著地抑制细胞内ALP活性(P<0.01);1 mmol/L钙能极显著的使成骨细胞滞留在S期(P<0.01);添加不同浓度的钙均能使G2期显著或极显著的增加(P<0.05或P<0.01),G1期极显著的下降(P<0.01),并能极显著地诱导细胞内骨桥蛋白的表达(P<0.01).表明添加不同浓度的钙均能抑制其早期分化,促进成骨细胞的增殖,使细胞滞留在S期或G2期,诱导细胞在基质成熟期分化,有利于细胞的钙化.     

盐胁迫下外源Ca~(2+)对红豆草幼苗抗性生理的影响

以蒙农红豆草为材料,研究了100mmol/L NaCl胁迫下不同浓度外源Ca2+对红豆草幼苗的生长、脯氨酸、可溶性糖和叶绿素含量及根系活力的影响;探讨了Ca2+对盐胁迫伤害的缓解作用。结果表明:随着Ca2+浓度的增加,与CK相比,红豆草脯氨酸、可溶性糖、叶绿素含量及根系活力呈先升高后降低的明显变化趋势,在T3(100mmol/L NaCl+30mmol/L CaCl2)处理下,红豆草脯氨酸、可溶性糖及叶绿素含量与对照相比提高了32.3%,60.0%和9.7%,差异显著(P0.05);T3、T4处理的根系活力显著高于CK(P0.05),其他处理与CK无明显差异;T3处理的株高显著高于对照CK(P0.05),其他处理与CK间无显著差异,达到最佳的效果。     

咪达唑仑对山羊不同脑区Ca~(2+)-Mg~(2+)-ATP酶活性的影响

为研究咪达唑仑对山羊不同脑区Ca~(2+)-Mg~(2+)-ATP酶活性的影响,探讨其在中枢麻醉的作用机制。试验用15只健康山羊,3只为生理盐水对照组,其余为试验组,试验组山羊肌肉注射14 mg/kg体重咪达唑仑。分别在给药后诱导期、麻醉期、恢复Ⅰ期和恢复Ⅱ期4个时间点,每点剖杀3只山羊取脑组织,采用分光光度法测定不同脑区Ca~(2+)-Mg~(2+)-ATP酶活性。结果注射咪达唑仑能明显抑制山羊大脑、丘脑、小脑和脑干的Ca~(2+)-Mg~(2+)-ATP酶活性,这种变化趋势与山羊肌肉注射咪达唑仑麻醉后行为学变化基本一致,海马的Ca~(2+)-Mg~(2+)-ATP酶活性在整个麻醉过程中无明显变化。表明咪达唑仑的麻醉作用可能与抑制山羊大脑、丘脑、小脑和脑干的Ca~(2+)-Mg~(2+)-ATP酶活性相关。     

肉苁蓉水提液对大鼠成骨细胞骨形态发生蛋白2基因表达的影响

本试验采用酶消化法分离得到大鼠颅骨成骨细胞,取第3代成骨细胞,通过加入不同浓度的肉苁蓉水提液(5×10^-5~5×10^-1 mg/mL)来提取细胞总RNA,再采用实时荧光定量PCR方法,来观察不同浓度的肉苁蓉水提液对大鼠成骨细胞骨形态发生蛋白2(bone morphogenetic protein 2,BMP2)基因表达的变化。从试验结果可以得出,肉苁蓉水提液对大鼠成骨细胞BMP2基因表达具有促进作用。     

内毒素对肝脏p53表达及Ca2+浓度的影响

为探讨内毒素在致大鼠肝损伤过程中对肝脏p53表达及Ca2+浓度的影响,将48只SD大鼠随机分2组:Ⅰ组为NS对照组;Ⅱ组为ET致病组,2组大鼠分别于第3、4、8、12h每组各处死6只,采集肝脏分别用于p53表达的Western-blotting检测和Ca2+浓度的FCM检测。结果显示,Ⅱ组p53的表达明显高于Ⅰ组(P<0.01),且Ⅱ组一直呈上升趋势;Ⅱ组Ca2+的荧光指数明显高于Ⅰ组(P<0.01),且一直呈上升趋势。结果表明,ET能有效上调肝细胞p53蛋白的表达及Ca2+浓度。     

麦角甾苷及松果菊苷对体外培养大鼠成骨细胞BMP2基因表达的影响

为了观察麦角甾苷和松果菊苷对体外培养大鼠成骨细胞BMP2基因表达的影响.本试验采用酶消化法分离得到大鼠颅骨成骨细胞,在第3代成骨细胞中分别加入含有不同浓度麦角甾苷和松果菊苷的培养液进行培养,在培养的不同时间收集细胞、提取细胞总RNA,采用实时荧光定量PCR方法观察对成骨细胞BMP2基因表达的影响.结果表明,麦角甾苷和松...     

桑树Ca~(2+)/H~+反向转运体基因MCAX-1的克隆及序列与表达分析

植物体内的Ca2+/H+反向转运体在Ca2+介导的营养和信号转导中发挥着重要作用。选择桑树幼叶cDNA文库中功能注释为Ca2+/H+反向转运体基因(CAX)的一条EST序列设计引物,通过cDNA末端快速扩增(RACE)与反转录PCR(RT-PCR)在桑品种育71-1的幼叶中克隆获得该基因的全长cDNA序列,命名为MCAX-1(GenBank登录号:JN716318)。序列分析显示:MCAX-1全长1 784 bp,包括197 bp的5'端非翻译序列和243 bp的3'端非翻译序列,含有一个1 344 bp的完整ORF,编码447个氨基酸残基,预测蛋白质分子质量为47.93 kD,等电点为5.67。构建的桑树和其它植物基于CAX蛋白氨基酸序列的系统进化树显示:桑树与盐地碱蓬(Suaeda salsa)、毛果杨(Populus trichocarpa)、蓖麻(Ricinus communis)等有较近的亲缘关系。半定量RT-PCR分析表明:MCAX-1在桑树幼芽、嫩叶、根和幼花中的表达量较高,在韧皮部、木质部和成熟果实中的表达量较低;MCAX-1在低温胁迫下的表达量减少,-1℃时几乎无表达,在干旱胁迫下的表达量随着胁迫时间延长逐渐达到最大值之后又迅速降低,在盐分胁迫初期的表达量无变化,但胁迫18 d时表达量明显降低。初步推测MCAX-1与桑树的抗逆性能有一定关联。     

铝暴露对鸡大脑组织钙稳态的影响

以1周龄海蓝白蛋鸡为实验对象,采用连续腹腔注射的方法建立铝中毒模型,研究铝对鸡大脑组织钙稳态的影响.实验设对照、低、中、高4个剂量组,暴露剂量分别为0、18.31、27.47、36.62mg/(kg·d)(Al3 ),染铝60d后,用原子吸收分光光度法检测鸡大脑组织中铝的含量,以Fura-2/AM作为细胞内游离钙离子荧光指示剂,检测鸡大脑神经细胞中游离钙离子浓度([Ca2 ]i),采用半定量RT-PCR法检测鸡大脑组织中钙调蛋白(CaM)mRNA的表达.结果表明,各染铝组鸡大脑组织铝含量、神经细胞[Ca2 ]i显著高于对照组(P＜0.05,P＜0.01),CaMmRNA表达水平显著低于对照组(P＜0.05,P＜0.01);且呈剂量-效应关系.提示铝暴露可致鸡大脑神经细胞内钙稳态失调.     

Effect of feeding garlic leaf on microbial nitrogen supply,kinetics of plasma phenylalanine,tyrosine and protein synthesis in sheep

The objective of the present study was to assess the feeding effects of garlic leaf on microbial N supply (MNS), turnover rates of plasma phenylalanine (PheTR) and tyrosine (TyrTR) and whole body protein synthesis (WBPS) in sheep. The sheep were fed either mixed hay (Hay‐diet, as control) or hay plus garlic leaf diet (GL‐diet, at a ratio of 9:1) in a crossover design each for a 21 day period. The isotope dilution method using [²H₅]Phe and [²H₂]Tyr was performed on the 21st day of each dietary treatment. Nitrogen intake remained similar between the diets and N absorption and N digestibility were higher (P < 0.05) in the GL‐diet than Hay‐diet. Total purine derivatives excretion and MNS were greater (P < 0.05) in the GL‐diet than the Hay‐diet. Plasma PheTR tended to be higher (P = 0.06) during GL feeding and TyrTR did not differ between the diets. Further, WBPS tended to be greater (P = 0.05) for the GL‐diet compared with the Hay‐diet. Hence, the present results suggest that garlic leaf may have positive effects on N metabolism by influencing MNS in sheep and could be used as a potential ruminant feed in the future.     

Effect of Chinese herbal medicine on kinetics of plasma phenylalanine,tyrosine and whole body protein synthesis in sheep

The aim of this study was to evaluate the effect of feeding decoction of a traditional nourishing Chinese herbal medicine formula on rates of plasma phenylalanine and tyrosine turnover and whole body protein synthesis in sheep. Ruminal fermentation characteristics and blood metabolites were also determined. Six sheep were subjected to either mixed hay (MH‐diet, as control) or MH‐diet supplemented with 2% of Chinese herbal medicine (mixture of Astragalus root, Angelica root, and Atractylodes rhizome; CHM‐diet) in a crossover design for each of 3‐week period. The isotope dilution of [²H₅]phenylalanine and [²H₂]tyrosine was performed as a primed‐continuous infusion to measure plasma phenylalanine and tyrosine kinetics. Concentrations of total volatile fatty acid, acetate, and propionate in the rumen tended to be higher (p < 0.10), and the pH value was lower (p = 0.04) for the CHM‐diet than the MH‐diet. Turnover rates of plasma phenylalanine and tyrosine tended to be higher (p < 0.10) for the CHM‐diet than the MH‐diet. Furthermore, whole body protein synthesis was greater (p = 0.04) for the CHM‐diet compared with the MH‐diet. The Chinese herbal medicine improved rumen fermentation and enhanced protein metabolism in sheep. Hence, it is suggested that the decoction of Chinese herbal medicine formula could be considered as a potential feed additive for ruminant production.     

骨碎补水提液对大鼠成骨细胞OPG mRNA表达的影响

通过探讨骨碎补水提液对大鼠成骨细胞中OPG mRNA水平表达的影响,来研究骨碎补对成骨细胞产生作用的分子机制。细胞培养48h后,应用荧光定量RT-PCR方法检测不同浓度骨碎补水提液及雌激素受体抑制剂ICI 182780作用后,细胞中OPG mRNA水平表达的变化。结果显示,骨碎补水提液作用于大鼠成骨细胞48h后,与对照组相比,高浓度骨碎补水提液显著上调OPG mRNA的比值,而低浓度组与对照组无显著差异。加入雌激素受体抑制剂ICI 182780后,骨碎补对OPG mRNA水平的促进作用消失。表明骨碎补水提液能上调OPG mRNA水平的表达,且呈剂量依赖性。上述促进作用能被雌激素受体抑制剂阻断,因而可以推测这个过程与雌激素受体通路有关。     

不同浓度Ca2+对塔里木马鹿冻融精子体外获能及蛋白酪氨酸磷酸化的影响

为探讨不同浓度Ca²⁺对马鹿精子体外获能的影响,本研究以塔里木马鹿冻融精子为试验材料,将精子分别悬浮于含不同浓度Ca²⁺（0、1.1、2.2、3.5、5.0 mmol/L）的台氏液（sp-TALP液）中,在培养0、2、4 h时,采用金霉素（CTC）染色法评价精子获能状态,采用SDS-PAGE分离精子膜蛋白,进行免疫印迹分析,检测酪氨酸磷酸化蛋白的表达水平。结果表明,Ca²⁺浓度为1.1、2.2 mmol/L有利于精子活力的维持（P<0.05）,精子获能率极显著高于对照组和高浓度组（3.5、5.0 mmol/L;P<0.01）,精子存活时间最长（P<0.01）,但高浓度Ca²⁺（5.0 mmol/L）对精子活力具有显著抑制作用（P<0.05）,精子获能率极显著低于低浓度组（P<0.01）,精子存活时间最短（P<0.01）;另外,随着培养时间的推移精子发生酪氨酸磷酸化蛋白的表达水平有所不同,培养2、4 h时,1.1 mmol/L组精子蛋白磷酸化水平极显著高于其他各组（P<0.01）,高浓度Ca²⁺（3.5、5.0 mmol/L）组酪氨酸磷酸化蛋白的表达水平极显著下降（P<0.01）。结果表明,塔里木马鹿精子体外获能所需的适宜Ca²⁺浓度为1.1 mmol/L,且获能过程中Ca²⁺的存在是必要的。     

氟对体外培养绵羊成骨细胞Bcl-2和Bax基因表达的影响

目的:探讨氟对体外培养成骨细胞凋亡相关基因Bcl-2和Bax基因表达的影响。方法:采用酶完全消化法分离2～3月龄胎羊颅盖骨成骨细胞,加入不同浓度(0～10-3mol/L)NaF,作用24h后,提取细胞总RNA并反转录成cDNA,通过实时荧光定量PCR方法,检测成骨细胞Bcl-2和Bax基因表达的变化。结果:1.0×10-5mol/LNaF组Bcl-2基因表达水平较对照组高,其他组Bcl-2表达水平均比对照组低;各NaF浓度组Bax基因表达量均比对照组高,且5.0×10-4mol/L组最高;除1.0×10-5mol/LNaF组外,Bcl-2/Bax比值均比对照组低,且5.0×10-4mol/L组最低。结论:高浓度NaF可能增加成骨细胞线粒体膜的通透性,下调Bcl-2 mRNA表达,上调Bax mRNA的表达,可能启动了线粒体凋亡信号转导途径。     

Improving the quality of rice straw by urea and calcium hydroxide on rumen ecology,microbial protein synthesis in beef cattle

Four rumen‐fistulated beef cattle were randomly assigned to four treatments according to a 4 × 4 Latin square design to study the influence of urea and calcium hydroxide [Ca(OH)₂] treatment of rice straw to improve the nutritive value of rice straw. Four dietary treatments were as follows: untreated rice straw, 50 g/kg urea‐treated rice straw, 20 g/kg urea + 20 g/kg calcium hydroxide‐treated rice straw and 30 g/kg urea + 20 g/kg calcium hydroxide‐treated rice straw. All animals were kept in individual pens and fed with concentrate at 0.5 g/kg of BW (DM), rice straw was fed ad libitum. The experiment was conducted for four periods, and each period lasted for 21 days. During the first 14 days, DM feed intake measurements were made while during the last 7 days, all cattle were moved to metabolism crates for total faeces and urine collections. The results revealed that 20 g/kg urea + 20 g/kg calcium hydroxide‐treated rice straw improved the nutritive value of rice straw, in terms of dry matter intake, digestibility, ruminal volatile fatty acids, population of bacteria and fungi, nitrogen retention and microbial protein synthesis. Based on this study, it could be concluded that using urea plus calcium hydroxide was one alternative method to improve the nutritive value of rice straw, rumen ecology and fermentation and thus a reduction of treatment cost.