乳铁蛋白营养作用

乳铁蛋白是一种具有多种生物活性功能的铁结合蛋白。本文主要阐述了乳铁蛋白在促进铁吸收、抑菌杀菌、免疫调节、调整肠道菌群和抗氧化等方面的生理功能,并讨论了影响乳铁蛋白生物活性的因素及乳铁蛋白在动物生产中的应用。     

牛乳铁蛋白提纯方法的建立与电泳分析

乳铁蛋白（Lactoferrin，Lf）又称“乳转铁蛋白”，是一种广泛存在于人和大多数哺乳动物乳中，具有广谱抗菌性、抗病毒、增强免疫、抗氧化、促进铁的传递和吸收、平衡肠道菌群等作用。     

乳铁多肽及其生物学活性的研究进展

乳铁多肽(乳铁素)是乳铁蛋白在酸性环境下经胃蛋白酶水解,产生的具有特殊生理功能的活性多肽。乳铁素不仅保持乳铁蛋白的活性,而且活性要比乳铁蛋白更强。乳铁素具有抑菌、杀菌、抗癌、抗病毒、免疫调节等多种乳铁蛋白所具有的活性。乳铁素的抗菌活性很强,但其抗病毒活性相对较弱。文章讨论了乳铁素成员中活性较强的牛乳铁素和人乳铁素,内容涵盖了目前乳铁素研究的重点领域,讨论了乳铁素的作用范围及其作用机制,探讨了乳铁素结构与活性之间的联系。     

乳铁蛋白的研究进展及应用前景

乳铁蛋白(LF)是一种多功能的糖蛋白,具有抗菌、抑菌、抗病毒、抗氧化、调节机体免疫和提高肠道对铁离子的吸收等作用。通过对乳铁蛋白的生产制备和基因调节作用的阐述,讨论乳铁蛋白在饲料添加剂中的应用前景。     

乳铁蛋白及其活性肽的营养生理作用及应用前景

乳铁蛋白(LF)是一种多功能的糖蛋白,乳铁蛋白活性多肽(Lfcin)是从LF上被胃蛋白酶水解下来的25个氨基酸残基的小肽。文中阐述了乳铁蛋白及其活性多肽的结构,介绍了乳铁蛋白及其活性多肽的主要生理作用:抗菌、抑菌、抗病毒、抗氧化,调节机体的免疫和提高肠道对铁离子的吸收等作用。根据乳铁蛋白制备的研究进展,讨论了乳铁蛋白及其活性多肽在乳、食品和动物生产中作为添加剂的应用前景。     

乳铁蛋白免疫佐剂作用的研究

乳铁蛋白是一种铁结合性糖蛋白,具有抗菌、抗病毒、抗肿瘤、免疫调节等多种生理功能,在食品、医药、饲料和化妆品等领域具有非常广阔的应用前景.作者对乳铁蛋白的免疫作用进行了研究,结果证明乳铁蛋白可以提高疫苗的免疫效果,具有较好的免疫佐剂作用.     

乳铁蛋白的免疫功能及其在养猪生产上的应用

乳铁蛋白是一种具有多功能的非血红素铁结合糖蛋白,免疫调节作用是其重要的生物学功能之一。文章主要从乳铁蛋白对体液免疫调节,细胞免疫调节,单核巨噬细胞的影响和自然杀伤细胞的影响四个方面进行阐述,并对乳铁蛋白在养猪生产上的应用作以介绍。     

乳铁蛋白抗奶牛乳房炎作用的探讨

1乳铁蛋白及其功能乳铁蛋白是一种广泛分布于家畜乳中的铁结合糖蛋白,其分子量为80kd,由一条单肽链组成,每分子上存在两个铁结合位点。乳铁蛋白主要由乳腺上皮细胞合成,少量来自多形核白细胞。目前已发现乳铁蛋白有多种生物学功能,如调节铁离子的吸收、促进淋巴细胞的生长、参与巨噬细胞、粒细胞和中性白细胞的调节,促进双歧菌的生长,抗菌作用等。抗菌作用是其最主要的功能之一。奶牛处于不同时期时,乳中的乳铁蛋白含量差异很大(如初乳中乳铁蛋白约为0.6g/mL,泌乳期降为0.01～0.1g/L,在干乳期乳铁蛋白含量则升高到2.0g/L)。当奶牛处于不同…     

乳铁蛋白生物学功能研究进展

乳铁蛋白(LF)是一种由外分泌腺和中性粒细胞分泌的多功能阳离子糖蛋白,广泛存在于大部分生物体液中,具有调节机体的铁代谢、增强机体的抗菌抗病毒能力、调节机体免疫力等多种功能。乳铁蛋白主要通过3种方式发挥其生物学功能:1)与铁紧密结合发挥营养免疫功能;2)与革兰氏阴性菌细胞壁外壁的脂多糖(LPS)结合进而使细菌溶解发挥杀菌作用;3)作用于免疫因子和各种免疫细胞以发挥其免疫调节作用。为了进一步挖掘乳铁蛋白的功能、促进其产品开发及其在食品与饲料工业中的应用,本文对乳铁蛋白的生物学功能进行了综述。     

乳铁蛋白的分子特性及其基因表达调控研究进展

乳铁蛋白是一种铁结合性糖蛋白，广泛存在于哺乳动物的分泌物中。研究报道，乳铁蛋白具有多种生物学功能。作者就乳铁蛋白的分子特性、生物学功能、作用机理以及基因表达调控方面的研究作了简要评述。     

乳铁蛋白生物学特性及其在断奶仔猪生产中的应用研究

乳铁蛋白是一种存在于哺乳动物外分泌液中的非血红素铁结合性糖蛋白,它具有多种生物活性功能.本文主要就乳铁蛋白的生物学功能及其在仔猪中生产中的应用前景做一综述.     

Evaluation of the protective effect of bovine lactoferrin against lipopolysaccharides in a bovine mammary epithelial cell line

Lactoferrin (Lf) is a non-haem iron-binding glycoprotein with a molecular weight of about 80 kDa, synthesized by glandular epithelial cells and stored in the secondary granules of neutrophils. The physiological significance of Lf is related to non-specific immune defence against pathogens, immunomodulatory activity, iron homeostasis, antioxidant properties and regulation of cell growth. Lf is a bioactive component of the mammary secretions and its modulatory and defensive functions do affect the newborn and the mammary gland as well. In this work a bovine mammary epithelial cell line (BME-UV1) was used as an in vitro model of the bovine mammary epithelium to examine the protective role of exogenous bovine Lf (bLf) against the cytotoxic damage induced by bacterial lipopolysaccharides (LPS) and the endogenous bLf mRNA expression after LPS exposure. In the in vitro model used, exogenous bLf exerts a protective effect against endotoxin cytotoxicity, which could be mediated by the LPS-neutralizing capability of bLf. In addition, in BME-UV1 cells the response to LPS exposure does not involve bLf mRNA expression, suggesting that this cell line lack of functional LPS-responsive elements.     

The in vitro effect of bovine lactoferrin on the activity of organ leukocytes in rainbow trout (Oncorhynchus mykiss), European eel (Anguilla anguilla) and wels catfish (Silurus glanis)

Lactoferrin (LF) is a glycoprotein found in milk, neutrophil granules, secretions and selected organs of mammals. Lactoferrin exhibits antibacterial, antiviral, fungicidal, immunoregulatory and other functions. Although fish are devoid of this protein and its cell receptors, LF effect on the immune mechanisms of fish has been demonstrated. The objective of this study was to investigate the effect of bovine lactoferrin, applied in vitro, on the activity of head kidney and spleen leukocytes in three freshwater fish species: rainbow trout (Oncorhynchus mykiss), European eel (Anguilla anguilla) and wels catfish (Silurus glanis). The obtained results validate LF beneficial effect on the respiratory burst of phagocytes in rainbow trout and wels catfish despite the fact that the potential killing activity against Aeromonas hydrophila was not stimulated in any of the studied species. Bovine lactoferrin enhanced the proliferation of T-lymphocytes in rainbow trout and European eel, as well as of B-lymphocytes in rainbow trout.     

乳铁蛋白在猪病防治及饲料中的应用

本文概述了乳铁蛋白的分子结构及其生物学功能,从促进铁的吸收、调节免疫、抗菌、抗病毒、抗氧化等生理功能方面说明其在仔猪疾病防治及饲料中的应用前景。     

Supplementation of corn seed with regular diet modulates immune function and antioxidant status in Capra hircus

Melatonin modulates the functional activation of antioxidative enzymes to maintain the oxidant–antioxidant balance in the physiological system. Melatonin administration via subcutaneous injection increases endogenous melatonin concentration that has been used to modulate the immune function in rodents and reproductive activity in small ruminant like goats. However, to date, no report exist which could suggest the effect of corn seed supplementation on the endogenous melatonin concentration and its impact on cellular‐immune function and antioxidative enzymes activity in any small ruminant like goats. Therefore, in this study, Zea mays (corn seeds), as source of melatonin, were supplemented with regular diet to explore its impact on endogenous melatonin concentration in goat, Capra hircus. Zea mays supplementation with regular diet for 40 days significantly elevated the endogenous melatonin concentration, proliferative response of peripheral blood mononuclear cells and antioxidative enzymes activity along with total antioxidant capacity of the plasma. An increase in circulatory IL‐2 and IL‐6 level along with declined TNF‐α, malondialdehyde and nitric oxide was noted with elevated endogenous melatonin concentration. In conclusion, it might be suggested that corn seed could be used as supplement to modulate endogenous melatonin concentration that may improve cellular‐immune function and antioxidant status. The corn seed might also be included as nutraceutical in regular diet to maintain immune‐antioxidant homoeostasis in other species.     

牛乳铁蛋白的研究与应用

乳铁蛋白广泛分布于哺乳动物具有分泌功能的组织及其分泌液中,其生物学功能广泛。本文通过介绍牛乳铁蛋白的结构、功能及其在生产、生活中的应用,分析讨论了其应用前景和利用基因工程技术方法生产的优势,以期为牛乳铁蛋白相关的理论研究和生产应用提供参考。     

乳铁蛋白及乳铁蛋白肽结构抗菌功能及基因表达

乳铁蛋白 (LF)是一种天然的铁结合蛋白。乳铁蛋白肽 (Lfcin)是从LF上被胃蛋白酶水解下来的 2 5个氨基酸残基的小肽。本文综述了LF和Lfcin的结构、抗菌功能和基因表达调控的研究进展     

Increased indices of lipid peroxidation in stress-susceptible pigs and effects of vitamin E

When stress-susceptible and stress-resistant pigs consumed diets containing 10 iu vitamin E kg-1, the stress-susceptible pigs had damaged cell membranes. This was indicated by increased plasma activities of creatine kinase and pyruvate kinase. Plasma concentrations of thiobarbituric acid reactive substances and conjugated dienes were also increased suggesting that the membrane damage was caused by free radicals. Susceptibility to free radicals was further demonstrated by an increased tendency for erythrocytes and tissue homogenates from stress-susceptible pigs to peroxidise when incubated with hydrogen peroxide and iron, respectively. Supplementation of the diets with approximately 20 times normal requirements of vitamin E decreased plasma creatine kinase and pyruvate kinase activities, and inhibited the formation of the indices of peroxidation in vivo and in vitro. It is concluded that the stress-susceptible pig has an abnormality in its antioxidant defence mechanisms. However, this abnormality was not due to a deficiency in selenium-dependent glutathione peroxidase, since activities were significantly increased in the longissimus dorsi of stress-susceptible pigs. Although the nature of the antioxidant defect is unclear, it is suggested that stress-susceptible pigs are under a sustained oxidant stress and that a decreased ability to accommodate even a normal free radical load may contribute to the rapid development of the fatal stress response.     

Effect of lactoferrin on selected immune system parameters and the gastrointestinal morphology in growing calves

Lactoferrin (LF) is a cationic iron-binding glycoprotein that is abundantly expressed and secreted from glandular epithelial cells and a prominent component of the secondary granules of polymorphonuclear neutrophils. Various in vitro and in vivo experiments demonstrate anti-microbial, -viral, -mycotic and -inflammatory effects of LF, associated with modulations of the immune system. Effects of oral administered LF on selected immune system parameters were studied in calves. Five calves were fed LF beginning on day 3 of life with colostral milk and starting on day 6 of life milk replacer enriched with 0.16% LF was fed. The average daily intake of LF per calf was 1.5-1.6 g/day. Additional five calves served as control group with identical treatment except for the LF supplementation. At the end of the study (day 61 of life), all calves were slaughtered and various tissues were sampled for histological and gene-expression studies. LF given orally was shown to act as an immunomodulatory agent by enhancing the size of Peyer's patches in the ileum and increasing blood serum immunoglobulin G levels. In addition, the number of peripheral blood leucocytes increased and mRNA levels of various interleukins (IL) such as IL-1beta, IL-8, IL-10 and interferon gamma (IFNgamma) in those cells in response to LF treatment were enhanced. In blood, the mRNA expression of the pro-inflammatory marker genes IL-1beta and IFNgamma decreased over 10-week treatment. Additionally, LF feeding decreased villus sizes in the jejunum. Together these findings emphasize the ability of LF to stimulate prominent immune system parameters and that it has the capacity to modulate the immune responses in a positive way.