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本文介绍了有关代谢网络,网络刚性和代谢工程的基本观点,特别是关于网络刚性和载流途径的工作假设,还讨论了代谢工程的应用与面临的难题。 相似文献
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基元模式分析是应用最广泛的代谢途径分析方法。基元模式分析的研究对象从代谢网络发展到信号传导网络;研究尺度从细胞到生物反应器,甚至生态系统;数学描述从稳态分解到动态解析;研究领域从微生物代谢到人类疾病。以下综述了基元模式分析的算法和软件开发现状,以及其在代谢途径与鲁棒性、代谢通量分解、稳态代谢通量分析、动态模型与生物过程模拟、网络结构与调控、菌株设计和信号传导网络等方面的应用。开发新的算法解决组合爆炸问题,探索基元模式与代谢调控的关系以及提高菌株设计算法效率是今后基元模式的重要发展方向。 相似文献
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Debate on the mechanism(s) responsible for the scaling of metabolic rate with body size in mammals has focused on why the maximum metabolic rate (VO2max ) appears to scale more steeply with body size than the basal metabolic rate (BMR). Consequently, metabolic scope, defined as VO2max/BMR, systematically increases with body size. These observations have led some to suggest that VO2max, and BMR are controlled by fundamentally different processes, and to discount the generality of models that predict a single power-law scaling exponent for the size dependence of the metabolic rate. We present a model that predicts a steeper size dependence for VO2max than BMR based on the observation that changes in muscle temperature from rest to maximal activity are greater in larger mammals. Empirical data support the model's prediction. This model thus provides a potential theoretical and mechanistic link between BMR and VO2 max. 相似文献
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恒温脊椎动物最大持续能量代谢率及其研究进展 总被引:1,自引:0,他引:1
研究最大持续代谢率具有重要的理论和实践意义,本文概述了近年来国外对脊椎动物最大持续代谢率研究的成果,概括介绍了限制最大持续代谢率的四个假说:(1)食物限制假说(food limit hypothesis) ,(2)外周限制假说(peripheral limit hypotheisis),(3)中心限制假说(central limit hypothesis)和(4)对称性形态构成假说(symmorphosis hypothesis),分析了静止代谢率随持续代谢率的增加而增加的机理,讨论了最大持续代谢率对动物的生态进化意义,最后指出了最大持续代谢率研究中可能的发展前景。 相似文献
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Metabolic scope and its utilization in relation to feeding and activity were measured in individual and grouped zebrafish (weight range, 430–551 mg) at 24° C by respirometry. Mean maximum metabolic rate, induced by swimming to exhaustion, Rmax(i), was 1223 (s.d. , 157) mg O2, kg?1 h?1 for individuals. Standard metabolic rate, Rs. was 364 mg O2 kg?1 h?1, as estimated by extrapolating to zero activity from measurements of unfed, spontaneously active individuals. Mean routine metabolic rate, Rrout, of individuals was 421 (s.d. , 58) mg O2, kg-1 h-1. The mean voluntary maximum metabolic rate, Rmax(v), following transfer of minimally exercised fish to the respirometer, was 1110 (s.d. , 83) mg O2 kg ?1 h?1 for groups of six fish, and was not significantly different from the value measured for individuals, 1066 (s.d. , 122) mg O2, kg?1 h?1. Grouped fish acclimated to the respirometer more slowly than individual fish and exhibited significantly higher Rrout, apparently a result of greater social interaction and activity in groups. Mean Rrout for groups was 560 (s.d. , 78) mg O2, kg?1 h?1. While groups of zebrafish fed a ration of 5% wet body weight day?1 exhibited consistently higher metabolic rates than fish fed rations of 2.5% wet body weight day?1 the high ration group still used only a maximum of 77% of the metabolic scope. Zebrafish of the size studied do not appear to demonstrate a high degree of conflict in utilization of metabolic scope by different respiratory components. The metabolic rates measured for zebrafish are among the highest yet measured for fish of similar size and at similar temperatures. 相似文献
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Central nervous system regulation of mammalian hibernation: implications for metabolic suppression and ischemia tolerance 总被引:1,自引:0,他引:1
Drew KL Buck CL Barnes BM Christian SL Rasley BT Harris MB 《Journal of neurochemistry》2007,102(6):1713-1726
Torpor during hibernation defines the nadir of mammalian metabolism where whole animal rates of metabolism are decreased to as low as 2% of basal metabolic rate. This capacity to decrease profoundly the metabolic demand of organs and tissues has the potential to translate into novel therapies for the treatment of ischemia associated with stroke, cardiac arrest or trauma where delivery of oxygen and nutrients fails to meet demand. If metabolic demand could be arrested in a regulated way, cell and tissue injury could be attenuated. Metabolic suppression achieved during hibernation is regulated, in part, by the central nervous system through indirect and possibly direct means. In this study, we review recent evidence for mechanisms of central nervous system control of torpor in hibernating rodents including evidence of a permissive, hibernation protein complex, a role for A1 adenosine receptors, mu opiate receptors, glutamate and thyrotropin-releasing hormone. Central sites for regulation of torpor include the hippocampus, hypothalamus and nuclei of the autonomic nervous system. In addition, we discuss evidence that hibernation phenotypes can be translated to non-hibernating species by H(2)S and 3-iodothyronamine with the caveat that the hypothermia, bradycardia, and metabolic suppression induced by these compounds may or may not be identical to mechanisms employed in true hibernation. 相似文献
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The steady state content of adenine nucleotides, inorganic phosphate and glycolytic and tricarboxylic acid cycle intermediates were measured in freeze clamped plerocereoids of S. solidus taken from the body cavity of infected fish (non-activated plerocercoids) and the results compared with the metabolite levels in plerocercoids which had been cultured in vitro for 12 h (activated plerocercoids). Of the glycolytic intermediates, the levels of fructose-6-phosphate, fructose-1, 6-diphosphate, 3-phosphoglycerate, phosphoenolpyruvate and lactate all decreased on activation, the remainder of the glycolytic intermediates did not alter significantly. In contrast, the levels of the tricarboxylic acid cycle intermediates all increased 2–3 fold on activation, whilst the adenine nucleotides remained virtually unchanged. The differences in the steady state content in intermediary metabolites in activated and non-activated plerocereoids are discussed in relation to possible mechanisms of metabolic control. 相似文献
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植物代谢工程是一个很有发展前景的新兴学科。它可通过多种方法对植物的代谢流进行改造,如加速限制步骤的反应,改变分叉代谢途径的流向,构建代谢旁路,引入转录调节因子、信号因子、植物激素合成基因,扩展和构建新的代谢途径等方法进行。并取得了一些有意义的研究结果。 相似文献
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代谢工程——生物工程学科的新兴研究领域 总被引:3,自引:0,他引:3
代谢工程包括推理性代谢工程及逆代谢工程。针对限制生物活性的因素 ,从不同的途径设计代谢改变策略 ,采用重组DNA技术解除或削弱该影响 ,提高目的产物的产率 ,是生化工程学科提高生物活性的新兴研究领域。讨论了推理性代谢工程及逆代谢工程的设计及应用。 相似文献
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维生素C生物转化的代谢工程研究 总被引:1,自引:2,他引:1
本从代谢工程角度出发,综述维生素C(Vc)生物转化代谢研究进展。分别论述了3条产生Vc重要前体2-酮基-L-古龙酸(2-KLG)反应路线的代谢机制、反应酶系及代谢工程菌构建等方面的问题;并对Vc生物转化应用前景作了展望。 相似文献
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代谢网络定量分析研究进展 总被引:3,自引:0,他引:3
综述了代谢工程中代谢控制分析、代谢通量分析、生化系统理论、途径分析、控制论模型等定量分析方法的基本理论,以实例说明了这些方法的应用,并对代谢分析方法的发展进行了展望。 相似文献
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Jack P. Hayes 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1989,159(4):453-459
Summary I compared the maximal aerobic metabolic rates (
), field metabolic rates (FMR), aerobic reserves (
-FMR), and basal metabolic rates (BMR) of wild and recently captured deer mice from low (440 m) and high (3800 m) altitudes. To separate the effects of the thermal environment from other altitudinal effects, I examined mice from different altitudes, but similar thermal environments (i.e., summer mice from high altitude and winter mice from low altitude). When the thermal environment was similar,
, FMR, and aerobic reserve of low and high altitude mice did not differ, but BMR was significantly higher at high altitude. Thus, in the absence of thermal differences, altitude had only minor effects on the aerobic metabolism of wild or recently captured deer mice.At low altitude, there was significant seasonal variation in
, FMR, and aerobic reserve, but not BMR. BMR was correlated with
, but not with FMR. The significant positive correlation of BMR with
indicates a cost of high
, because higher BMR increases food requirements and energy use during periods of thermoneutral conditions.Abbreviations
BMR
basal metabolic rate
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FMR
field metabolic rate
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partial pressure of oxygen
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T
a
ambient temperature
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T
b
body temperature
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T
e
operative temperature
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maximal aerobic metabolic rate 相似文献
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Shorebirds have high resting and field metabolic rates relative to many other bird groups, and this is posited to be related to their high‐energy lifestyle. Maximum metabolic outputs for cold or exercise are also often high for bird groups with energetically demanding lifestyles. Moreover, shorebirds demonstrate flexible basal and maximal metabolic rates, which vary with changing energy demands throughout the annual cycle. Consequently, shorebirds might be expected to have high maximum metabolic rates, especially during migration periods. We captured least Calidris minutilla and pectoral C. melanotos sandpipers during spring and fall migration in southeastern South Dakota and measured maximal exercise metabolic rate (MMR; least sandpipers only), summit metabolic rate (Msum, maximal cold‐induced metabolic rate) and basal metabolic rate (BMR, minimum maintenance metabolic rate) with open‐circuit respirometry. BMR for both least and pectoral sandpipers exceeded allometric predictions by 3–14%, similar to other shorebirds, but Msum and MMR for both species were either similar to or lower than allometric predictions, suggesting that the elevated BMR in shorebirds does not extend to maximal metabolic capacities. Old World shorebirds show the highest BMR during the annual cycle on the Arctic breeding grounds. Similarly, least sandpiper BMR during migration was lower than on the Arctic breeding grounds, but this was not the case for pectoral sandpipers, so our data only partially support the idea of similar seasonal patterns of BMR variation in New World and Old World shorebirds. We found no correlations of BMR with either Msum or MMR for either raw or mass‐independent data, suggesting that basal and maximum aerobic metabolic rates are modulated independently in these species. 相似文献
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Marcel Klaassen 《Oecologia》1995,104(4):424-432
The circannual patterns in resting metabolic rate (RMR) of males of two subspecies of stonechats, the European Saxicola torquata rubicula and the East African S. t. axillaris, are compared. As the birds from the two subspecies were raised and kept under comparable laboratory conditions, differences in metabolic rate between the two subspecies had to be genetically determined. RMR peaked during moult in both subspecies. During the rest of the year RMR was fairly constant in both subspecies and assumed to reflect basal metabolic rate (BMR). African stonechats had a 22% lower mass specific BMR than European stonechats, which is thought to reflect a genetical physiological adaptation to the differences in environmental circumstances they experience in the field. A low BMR makes an animal more susceptible to cold. Hence, the relatively high plumage mass in the African compared to the European stonechat may be functionally linked to its relatively low BMR. Moult costs, calculated from the plumage masses and the differences in RMR inside and outside the moult period, tended to be higher in the European compared to the African stonechats. These data and an interspecific comparison of moult costs over various species of birds support the earlier notion by Lindström et al. (1993) that moult costs are more closely linked with BMR than with body mass or rate of moult. The relation between moult costs and BMR and the fact that the efficiency of moult is extremely low (3.8 and 6.4% for European and African stonechats, respectively) suggest that the maintenance of specific tissues necessary for moult is a large cost factor. Alternatively, impaired insulation during moult may necessitate an increased metabolic capacity which may be associated with an increased RMR. 相似文献