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1.
铁是机体代谢所必需的微量元素之一。近年来,铁在机体内的代谢越来越受到人们的重视。维持体内铁的平衡,对保证机体的正常生理功能显得极为重要。胞质铁蛋白(cytosolic ferrifin,CFt)是细胞内重要的调节铁平衡的因子之一。而近年发现的线粒体铁蛋白(mitochondrial ferritin,MtFt)是一种定位在线粒上、和铁代谢密切相关的蛋白,具有组织受限性表达的特点,它在结构和功能上与胞质铁蛋白相比有一定的相似性,但是由于其mRNA上没有铁调控元件,它的表达不直接受铁调节蛋白调控,所以其确切功能及表达机制还未完全明了,因此,近年来有不少人开展了这方面的研究。对线粒体铁蛋白的深入研究将极大地丰富人们对铁在亚细胞水平上的代谢机制和功能的认识。文章介绍了细胞质铁蛋白的调控机制以及线粒体铁蛋白的结构、功能、表达及与铁代谢的关系。 相似文献
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铁代谢与铁调素hepcidin 总被引:10,自引:0,他引:10
铁是机体必需的营养元素。然而,铁过载则导致细胞的损伤。由于生物体缺少排泄铁的机制,因而,肠铁吸收的调控便成为维持机体铁稳态的关键。新近研究发现hepcidin对机体铁稳态的调节起着至关重要的作用,被人们称为铁调节激素。Hepcidin主要在肝细胞中合成,之后分泌至血液将体内铁需要的信号传至小肠,调控肠铁的吸收。这一过程主要通过调节小肠铁转运相关蛋白的表达而实现。任何影响hepcidin表达的因素都可能破坏体内的铁平衡,造成铁代谢相关疾病。 相似文献
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最近的研究证实,肾小管细胞具有能力表达包括转铁蛋白受体1(transferrin receptor-1,TfR1)、二价金属离子转运蛋白1(divalent metal transporter-1,DMT1)、膜铁转运蛋白1(ferroportin-1,FPN1)、铁调节蛋白(iron regulatory protein,IRP)和铁调素(hepcidin,Hepc)在内的几乎所有铁代谢蛋白.这些蛋白质的存在以及相关研究显示肾脏可能具有排出多余铁的功能,因此对体铁平衡起有十分重要的作用. 相似文献
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铁元素为几乎所有的生命体所必需,维持铁代谢稳态对机体的正常功能至关重要。铁代谢紊乱与人类多种疾病的发生和发展有关。已知铁代谢稳态受到一系列参与铁代谢环节的关键蛋白质,如IRP2等的精确调节。这些重要蛋白质的稳定性、生理活性的动态变化及其协调作用是细胞维持铁代谢平衡的分子基础。除了转录和转录后水平的调控,泛素化等翻译后修饰方式和蛋白质降解是细胞精确调控参与铁代谢的蛋白质的水平及功能普遍而有效的方式之一;同时,细胞的铁代谢状态也影响细胞内参与泛素化等翻译后修饰途径的酶类的活性和稳定性,从而在铁代谢和蛋白质修饰.降解途径之间形成反馈机制,实时和动态地完成对细胞内铁代谢水平的精确调控。就相关领域的最新进展作简要综述。 相似文献
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目的:探讨去铁酮联合去铁胺治疗重型地中海贫血患儿的疗效及对血糖代谢和铁代谢的影响。方法:选取2015年3月~2017年12月期间海南省妇女儿童医学中心儿科收治的127例重型地中海贫血患儿,根据数表法将患儿随机分为对照组(n=63)和研究组(n=64),其中对照组在基础治疗的基础上给予去铁胺治疗,研究组在对照组的基础上联合去铁酮治疗。比较两组患儿临床疗效、治疗前后的血糖代谢和铁代谢情况,记录两组患儿治疗期间不良反应发生情况。结果:研究组患儿治疗后临床总有效率为73.44%(47/64),高于对照组患儿的55.56%(35/63)(P0.05)。两组患儿治疗后血糖代谢正常率均升高,且研究组高于对照组(P0.05)。两组患儿治疗后血清铁蛋白(SF)降低,尿铁排泄量(UIE)升高(P0.05);研究组治疗后SF低于对照组,UIE高于对照组(P0.05)。两组不良反应发生率比较无统计学差异(P0.05)。结论:去铁酮联合去铁胺治疗重型地中海贫血患儿,安全有效,可改善机体铁代谢,提高血糖代谢正常比例,具有一定的临床应用价值。 相似文献
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植物着丝粒结构和功能的研究进展 总被引:1,自引:0,他引:1
着丝粒是真核生物有丝分裂和减数分裂染色体正确分离和传递所必需的染色体区域。十多年来, 已对包括拟南芥、水稻、玉米在内的一些植物的着丝粒进行了较深入的分子生物学研究。在不同的植物间, 着丝粒DNA的保守性很低, 呈现快速进化, 但着丝粒的DNA序列类型和组织方式基本相似, 一般是由夹杂排列着的卫星DNA串联重复阵列和着丝粒专一的反转录转座子构成。与着丝粒DNA相反, 着丝粒/着丝点的结构性和瞬时蛋白质在包括植物在内的真核生物中保守。与其他真核生物的情况一样, 拥有含着丝粒组蛋白H3(CENH3)的核小体是植物功能着丝粒染色质最基本的特征, CENH3在着丝粒染色质的识别和保持中起着关键作用。 相似文献
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Current knowledge of iron metabolism 总被引:1,自引:0,他引:1
Boccio J Salgueiro J Lysionek A Zubillaga M Weill R Goldman C Caro R 《Biological trace element research》2003,92(3):189-211
Iron plays many roles in human physiology. In this article, we summarize the basic and current knowledge of this essential
micronutrient on human metabolism. 相似文献
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The effect of chromium on some parameters related to iron metabolism was investigated. Preliminary experiments showed that
this metal ion was taken up by serum proteins and was dependent on the amount of chromium present in the medium. It was also
shown that the uptake of iron was reduced significantly in the presence of chromium. In vivo study showed that the serum levels
of iron and total iron binding capacity (TIBC) were reduced by 28 and 11%, respectively, following daily administration of
chromium (1 mg/kg) for 45 d. Serum ferritin was reduced by 22% under this condition. Hematocrit and hemoglobin levels were
also affected in chromium-treated animals and were both reduced by 17%. Spectrophotometric titration of each individual amino
acid located in the iron binding site of transferrin revealed that tyrosin might be the most suitable ligand for the binding
of chromium to transferrin. These results suggest that chromium may compete with iron in binding to apo-transferrin, and influence
iron metabolism and its related biochemical parameters. 相似文献
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Yoshinobu Ohira Jack Hegenauer Paul Saltman V. Reggie Edgerton 《Biological trace element research》1982,4(1):45-56
Iron-deficiency anemia leads directly to both reduced hemoglobin levels and work performance in humans and experimental animals.
In an attempt to observe a direct link between work performance and insufficient iron at the cellular level, we produced severe
iron deficiency in female weanling Sprague-Dawley rats following five weeks on a low-iron diet. Deficient rats were compared
with normal animals to observe major changes in hematological parameters, body weight, and growth of certain organs and tissues.
The overall growth of iron-deficient animals was approximately 50% of normal. The ratio of organ weight: body weight increased
in heart, liver, spleen, kidney, brain, and soleus muscle in response to iron deficiency. Further, mitochondria from heart
and red muscle retained their iron more effectively under the stress of iron deficiency than mitochondria from liver and spleen.
Metabolism of iron in normal and depleted tissue was measured using tracer amounts of59Fe administered orally. As expected, there was greater uptake of tracer iron by iron-deficient animals. The major organ of
iron accumulation was the spleen, but significant amounts of isotope were also localized in heart and brain. In all muscle
tissue examined the59Fe preferentially entered the mitochondria. Enhanced mitochondrial uptake of iron prior to any detectable change in the hemoglobin
level in experimental animals may be indicative of nonhemoglobin related biochemical changes and/or decrements in work capacity. 相似文献
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Nitric oxide and changes of iron metabolism in exercise 总被引:12,自引:0,他引:12
Qian ZM 《Biological reviews of the Cambridge Philosophical Society》2002,77(4):529-536
Accumulated data imply that exercise itself might not lead to a true iron deficiency or 'sport anaemia' in a healthy athlete who has adequate iron intake. The higher prevalence of iron deficiency anaemia in younger female athletes might be not due to exercise itself, but probably results from dietary choices, inadequate iron intake and menstruation. These factors can also induce iron deficiency or anaemia in the general population. However, exercise does affect iron metabolism, leading to low or sub-optimal iron status. The underlying mechanism is unknown. In this review, recent advances in the study of the effect of exercise on iron metabolism and nitric oxide, and the relationship between nitric oxide and iron status in exercise are discussed. A hypothesis that increased production of nitric oxide might contribute to sub-optimal iron status in exercise is proposed. 相似文献
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The metabolism of iron (Fe) has been shown to interact with that of aluminum (Al) in relation to intestinal absorption, transport
in the blood plasma, and the induction of lipid peroxidation and cellular damage. Also, dietary supplementation with citrate
has been shown to increase the absorption of both metals and, in the presence of high intakes of Fe and Al, leads to excessive
accumulation of both metals in the body. In this study, the likely interaction between Al and internal Fe metabolism was investigated
using rats fed diets that were either deficient, sufficient, or loaded with Fe, with or without the addition of Al and sodium
citrate. These diets commenced when the rats were 4 wk old and were continued for 9–11 wk. At that time, Fe metabolism as
assessed by measurement of organ uptake of59Fe and125I-transferrin, after iv injection of transferrin labeled with both isotopes, plus measurement of tissue concentrations of
nonheme Fe and Al. The Fedeficient diet and Fe-loaded diet led to states of Fe deficiency and Fe overload in the rats, and
supplementation of the diet with Al increased Al levels in the kidneys, liver, and femurs, but, generally, only when the diet
also contained citrate. Neither Al nor citrate supplementation of the diet had any effect on nonheme Fe concentrations in
the liver, kidney, or brain, or on the uptake of59Fe or125I-transferrin by liver, kidney, brain, or spleen. Only with the femurs was a significant effect observed: increased59Fe uptake in association with increased Al intake. Therefore, using this animal model, there was little evidence for interaction
between Fe and Al metabolism, and no support was obtained for the hypothesis that dietary supplementation with Fe and citrate
can lead to excessive Fe absorption and deposition in the tissues. 相似文献
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铁作为一种必需的营养元素,在哺乳动物体内的重要作用越来越为人们所重视。动物体内存在着严格的铁代谢调节机制,以确保体内铁始终处于正常生理水平。如果铁代谢失调、体内铁缺乏或过负荷均会导致各种临床疾病。研究发现,肝脏抗菌多肽(hepcidin)很可能是一种控制小肠铁吸收及调节体内铁稳态的关键物质,是一种极为重要的铁调节激素。本文综述了铁的生理作用、铁缺乏引起的疾病(如:缺铁性贫血和儿童神经系统疾病)和铁过负荷引起的疾病(如:肝损伤、心血管疾病、帕金森病和癌症等),并对如何利用现代化技术手段在基因水平开展铁紊乱相关疾病的治疗做了展望。 相似文献
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We investigated the effect of exercise on iron metabolism in horses. Four horses were walked on a mechanical walker for 1
wk (pre-exercise). They then performed moderate exercise on a high-speed treadmill in the first week of the exercise and relative
high in the second week and high in the third week. Serum iron was significantly lower in the third week of exercise than
in the pre-exercise. Transferrin saturation (TS) was significantly lower in the first and third weeks of exercise than in
the pre-exercise. Serum haptoglobin was significantly lower in the first week of exercise than in the pre-exercise and further
significantly lower in the second and third weeks than in the first. The packed cell volume did not change during the experiment.
The exercise significantly increased the apparent absorption of iron. Urinary iron excretion did not change throughout the
experiment. Sweat iron loss did not change during the exercise. The exercise significantly increased iron balance. We considered
that hemolysis is induced by moderate exercise and is further enhanced by heavy exercise, which decreases serum iron and TS.
However, the increase in iron absorption compensates for the adverse effect of exercise on iron status. Therefore, exercise
does not induce anemia in horses. 相似文献
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《Animal : an international journal of animal bioscience》2013,7(10):1651-1658
Iron deficiency is the most common nutritional deficiency in the world. Special molecules have evolved for iron acquisition, transport and storage in soluble, nontoxic forms. Studies about the effects of iron on health are focused on iron metabolism or nutrition to prevent or treat iron deficiency and anemia. These studies are focused in two main aspects: (1) basic studies to elucidate iron metabolism and (2) nutritional studies to evaluate the efficacy of iron supplementation to prevent or treat iron deficiency and anemia. This paper reviews the advantages and disadvantages of the experimental models commonly used as well as the methods that are more used in studies related to iron. In vitro studies have used different parts of the gut. In vivo studies are done in humans and animals such as mice, rats, pigs and monkeys. Iron metabolism is a complex process that includes interactions at the systemic level. In vitro studies, despite physiological differences to humans, are useful to increase knowledge related to this essential micronutrient. Isotopic techniques are the most recommended in studies related to iron, but their high cost and required logistic, making them difficult to use. The depletion–-repletion of hemoglobin is a method commonly used in animal studies. Three depletion–-repletion techniques are mostly used: hemoglobin regeneration efficiency, relative biological values (RBV) and metabolic balance, which are official methods of the association of official analytical chemists. These techniques are well-validated to be used as studies related to iron and their results can be extrapolated to humans. Knowledge about the main advantages and disadvantages of the in vitro and animal models, and methods used in these studies, could increase confidence of researchers in the experimental results with less costs. 相似文献