共查询到18条相似文献，搜索用时 187 毫秒
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乳铁蛋白的营养生理作用及其作为饲料添加剂的应用 总被引：3，自引：0，他引：3
对乳铁蛋白的乳铁蛋白活性多太的结构及其动物体内的分布进行了分析，重点阐述了它们促进肠道铁离子的吸收，调节机体免疫机能，抑菌和抗菌活性，抗病毒，抗氧化，刺激肠道有益菌群生长，保护肠道等多种生理功能，总结了乳铁蛋白的测定方法，讨论了利用天然初乳制备乳铁蛋白和乳铁蛋白活性肽的的工艺和利用基因工程生产乳铁蛋白和乳铁蛋白活性肽。对乳铁蛋白和乳铁蛋白活性肽在饲料加工过程及动物肠道中的稳定性进行了分析，并初步讨论了乳铁蛋白和乳铁蛋白活性肽代替饲用抗生素作为饲料添加剂的应用前景。 相似文献
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实验用奶牛乳铁蛋白肽特异性PCR引物从奶牛乳腺组织中扩增奶牛乳铁蛋白肽基因,然后将其连入pCMV-N-eGFP载体中,构建奶牛乳铁蛋白肽的真核表达载体GFP-LfcinB,并将其转染进奶牛乳腺上皮细胞中,分别运用蛋白质免疫印记和牛津杯法等方法检测GFP-LfcinB蛋白在细胞中的表达及其对金黄色葡萄球菌的抗菌活性.结果表明,试验成功的建立了奶牛乳铁蛋白肽的真核表达载体GFP-LfcinB,并且此重组载体能在奶牛乳腺上皮细胞中正常表达具有抗金黄色葡萄球菌活性的GFP-LfcinB蛋白. 相似文献
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乳铁蛋白（LF）作为一种天然的具有免疫功能的糖蛋白，其多种生物学功能早在20世纪60年代就引起了人们普遍的关注。在食品方面，乳铁蛋白作为牛乳中天然的功能性强化剂已经成为众多乳品研发人员关注的焦点。乳铁蛋白在国外已广泛应用于乳制品中，尤其婴儿配方奶粉中的使用较多。在免疫方面，乳铁蛋白可以促进巨噬细胞或中性白细胞的杀菌作用和吞噬作用，调节NK细胞的活性和淋巴细胞、中性白细胞的增殖。 相似文献
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为了研究人乳铁蛋白对宫颈癌Hela细胞的生长抑制作用及其对细胞凋亡、p53蛋白表达和Caspase-3活性的影响,试验采用MTT方法检测细胞的生长抑制率、DNA片段化试验检测细胞凋亡、流式细胞术测定细胞周期、Western-blot检测p53蛋白表达、Caspase-3活性检测试剂盒检测Caspase-3的活性.结果表明:人乳铁蛋白对宫颈癌Hela细胞的抑制呈现时间和剂量依赖性,有73%的Hela细胞停滞在G0～G1期;Western-blot检测结果显示人乳铁蛋白可以上调p53蛋白的表达; 人乳铁蛋白作用48 h后Caspase-3的活性是0小时时的5.5倍,二者差异极显著(P<0.01).结果说明人乳铁蛋白能显著抑制宫颈癌Hela细胞生长,其抗肿瘤机制与诱导细胞凋亡、调控细胞周期、上调p53表达、活化Caspase-3有关. 相似文献
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乳铁蛋白和乳过氧化物酶是具有生物学活性的乳清蛋白,有益于消费者健康,但其生物学活性在高压处理过程中容易发生变性。对传统的食品热处理加工方法而言,高压处理因其具有抗微生物效果而不改变食品的感官和营养品质,是一种较好的替代方法。本试验研究了高压处理对脱脂乳和乳清中乳铁蛋白和乳过氧化物酶变性的影响,随着缓冲液中蛋白的分离,在20℃时控制压力范围在450～700MPa。乳铁蛋白的变性是利用夹心ELISA法测定其与特异性抗体反应性的丧失来衡量的。乳过氧化物酶变性是通过分光光度计测定其酶活的丧失而确定的。各处理组乳过氧化物酶均未真正失活。在每次压力处理过后,测定残留的具有免疫反应活性的乳铁蛋白浓度,数据进行动态分析以获得D和Z值。随着压力和持续时间的增加,乳铁蛋白变性增加,乳清中乳铁蛋白的D值较牛奶中偏低,且乳清和牛奶中的D值比磷酸盐缓冲液中低。因此,缓冲液和牛奶中的蛋白变性速度要慢于乳清中蛋白的变性。在以上3种介质中乳铁蛋白的变性遵循的反应级数为n=1.5。在脱脂乳、乳清和缓冲液中处理得到了乳铁蛋白的活性体积分别为-34.77、-24.35和-24.09mL/mol,说明压力导致了蛋白体积的下降。 相似文献
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乳铁蛋白的功能与用途 总被引：2，自引：0，他引：2
乳铁蛋白(Lactoferrin)是一种天然的蛋白质降解物,存在于牛乳和母乳中。乳铁蛋白虽称为蛋白,但从其分子结构及相对分子量上看仍属于活性肽。 乳铁蛋白的来源与理化性质: 1、乳铁蛋白的来源: 乳铁蛋白是一种与铁结合的蛋白质,存在於人奶及一切哺乳动物的奶中,也存在於唾液、泪液、气管、鼻腔分泌物、胰液以及其他的身体分泌物中。 各种哺乳动物都能产生乳铁蛋白,但其浓度因 相似文献
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乳铁蛋白肽具有杀菌、抗病毒、抗真菌等多种独特的生物学活性。综述了乳铁蛋白肽的结构、生物学功能、国内外研究动态及其应用前景,提出了其研究中存在的问题及相应对策。 相似文献
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A Bartoskova L Adlerova H Kudlackova L Leva R Vitasek M Faldyna 《Reproduction in domestic animals》2009,44(S2):193-195
The concentration of lactoferrin was measured in canine sera from groups of healthy male dogs as well as pregnant and non-pregnant female dogs and was compared with that of bitches with pyometra. Lactoferrin concentrations were higher in bitches with pyometra. The role of elevated lactoferrin concentrations in the suppression of lymphocyte activity was examined in sera from bitches with pyometra in a series of investigations. Although the sera from bitches with pyometra were capable of suppressing lymphocyte activity, lactoferrin was not found to be involved in this action. 相似文献
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Antimicrobial, anti-inflammatory and immunomodulating properties of lactoferrin have been demonstrated in mammals and in fish. However, in vivo, lactoferrin is digested by gastric pepsin treatment into the N-terminal derived peptide named lactoferricin. This has been so far overlooked in fish in vitro studies. The aim of the present study was to assess in vitro the effects of both lactoferricin and lactoferrin on the head kidney cells of European sea bass (Dicentrarchus labrax, L.) in order to determine their potential as dietary additives and to get some insight into their mode of action. In vitro lactoferricin decreased significantly the chemiluminescent response of head kidney cells but did not affect the zymosan-triggered chemiluminescence activity. On the other hand, a high concentration of lactoferrin directly stimulated chemiluminescence but reduced the zymosan-triggered chemiluminescence. The bactericidal activity of head kidney cells was also significantly diminished by pre-incubation with lactoferrin in a dose-dependent manner. Although no significant effect of lactoferricin or lactoferrin was evidenced on head kidney cellular viability, absent or negative effect on the priming of respiratory burst activity suggested that care should be taken when using lactoferrin in the diet of sea bass and high doses should be avoided. Hypotheses about the mechanisms of action of lactoferricin and lactoferrin are presented. 相似文献
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Diarra MS Petitclerc D Deschênes E Lessard N Grondin G Talbot BG Lacasse P 《Veterinary immunology and immunopathology》2003,95(1-2):33-42
Antibiotics should combine good antibacterial activity and the capacity to work in association with the host defence system. In this study, we have investigated the effects of bovine lactoferrin alone or in combination with penicillin G on the phagocytic activity of bovine polymorphonuclear leukocytes against Staphylococcus aureus. We have shown that susceptibility of S. aureus to phagocytosis was decreased in the presence of penicillin in the medium. In a kinetic study, lactoferrin alone did not affect phagocytosis but, when used with penicillin, it reversed the negative effect of this antibiotic on phagocytosis. In addition, in an epithelial invasion assay, lactoferrin alone or in combination with penicillin reduced the invasion of mammary epithelial cells in culture by S. aureus. Lactating female CD-1 mice were infected by intra-mammary delivery of a virulent penicillin-susceptible S. aureus strain and were then randomly assigned to treatments according to a 2 x 2 factorial design. In this mouse mastitis model, 2 days of systemic treatments with lactoferrin and/or penicillin did not lead to a total clearance of infection by S. aureus, but bacterial number was significantly reduced by treatments with lactoferrin or penicillin. These data suggest that bovine lactoferrin, alone or in combination with penicillin G, enhances S. aureus susceptibility to immuno-defense mechanisms, which can be beneficial in the treatment of S. aureus infections. 相似文献
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Polymorphonuclear (PMN) cells of more than 90% viability and 92% purity were isolated from the peripheral blood of buffaloes. The cationic proteins were extracted with 0.2 mol/L sodium acetate, pH 4.0 from the granules in the PMN and subjected to both non-denaturing and denaturing acid urea polyacrylamide gel electrophoresis (AUPAGE) for identification of myeloperoxidase (MPO), lysozyme, protease activity and lactoferrin. Protease was identified using -naphthyl acetate as substrate, while lactoferrin was identified using a reference lactoferrin from bovine milk in AUPAGE, and by double immunodiffusion and Western blot techniques. Based on AUPAGE, lysozyme was found to be most cationic of all the proteins and peptides from the PMN granules as was evident from reference lysozyme run. The results indicated that the granules in buffalo PMN cells have lysozyme, protease, MPO and lactoferrin. 相似文献
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论文旨在研究日粮中添加不同水平乳铁蛋白（lactoferrin,Lf）对早期断奶仔猪养分利用率、血清营养生化指标及血清酶活性指标的影响。采用单因素试验设计,选用21日龄断奶仔猪96头,随机分为4个处理,每个处理4个重复,每个重复6头仔猪,分别在基础饲粮中添加0、250、500和750 mg/kg乳铁蛋白。试验为期21 d。结果表明：添加乳铁蛋白有提高断奶仔猪干物质消化率的趋势（P＞0.05）,其中500 mg/kg添加组最高。 250 mg/kg、750 mg/kg组与对照组相比能显著提高粗灰分消化率（P＜0.05）;750 mg/kg乳铁蛋白组血清中尿素氮和总胆固醇的含量显著低于对照组（P＜0.05）,各乳铁蛋白添加组血清中总蛋白水平有提高的趋势（P＞0.05）;各乳铁蛋白添加组血清中谷丙转氨酶、谷草转氨酶、碱性磷酸酶、乳酸脱氢酶的活性与对照组差异不显著（P＞0.05）。综合试验结果与经济效益,本试验条件下日粮中添加500 mg/kg乳铁蛋白为最适添加量。 相似文献
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Objective To investigate the effects of bovine lactoferrin on in vitro replication of feline herpes virus (FHV‐1) and to determine at what points during viral replication these effects occur. Sample population Cultured Crandell‐Reese feline kidney (CRFK) cells and FHV‐1 strain 727. Procedure Five concentrations of bovine lactoferrin (0.5, 1, 2, 5, and 10 mg/mL) were added at one or more of three time points during conventional plaque reduction assays: (a) uninfected CRFK cells were incubated in lactoferrin‐containing medium for 30 min prior to viral adsorption; (b) virus was suspended in lactoferrin‐containing medium prior to and during adsorption, or (c) CRFK cells were incubated with lactoferrin‐containing medium for 48 h following viral adsorption. Plaques were counted and antiviral effect expressed as percent inhibition relative to control medium that contained no lactoferrin. Results Exposure of CRFK cells to lactoferrin prior to or during viral adsorption inhibited FHV‐1 replication by 87–96% (mean: 91%). Application of lactoferrin following viral adsorption had no appreciable effect on FHV‐1 replication. No additive or synergistic effects were noted when lactoferrin was added at multiple steps. These effects were similar at all concentrations of lactoferrin tested. Cytotoxic effects of lactoferrin on CRFK cells were not observed at any concentration tested. Conclusions and clinical relevance Bovine lactoferrin has a notable inhibitory effect on the in vitro replication of FHV‐1 prior to and during, but not following viral adsorption. These findings strongly suggest that lactoferrin inhibits FHV‐1 adsorption to the cell surface and/or penetration of the virus into the cell. Clinical effects of topical lactoferrin in acute or recrudescent herpetic episodes in cats warrant investigation. 相似文献
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Yamada Y Sato R Kobayashi S Hankanga C Inanami O Kuwabara M Momota Y Tomizawa N Yasuda J 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2008,70(5):443-448
Lactoferrin has several biological activities, including antitumor activities in some human and animal tumor cells. Clinical trials have been carried out in human medicine based on these effects. However, the antitumor effects of lactoferrin in veterinary medicine remain unknown. In this in vitro study, we demonstrated that co-incubation of canine mammary gland tumor cells (CIPp and CHMp) and bovine lactoferrin induced growth arrest of tumor cells. This growth arrest was associated with induction of G1 arrest. Furthermore, this effect was stronger in tumor cells than in normal cells. These findings demonstrate that bovine lactoferrin has anti-tumor activity in canine mammary tumors and has the potential for use in tumor-bearing dogs. 相似文献