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1.
Thermogenic metabolic curves were determined by the ampoule method at 303 K using a TAM air isothermal microcalorimeter in
mitochondria isolated from rice 9311 (Oryza sativa L). From the thermogenic curves the activity recovery rate constant k and the maximum heat power P
m were obtained. Both were positively correlated to the protein content of rice mitochondria. The corresponding correlation
coefficients were 0.9959 and 0.9950, respectively, indicating that the in vitro metabolic activity of mitochondria can be reliably expressed by these parameters. Addition of La (III) ions in concentrations
ranging from 0 to 130 μg/mL resulted in significantly higher k and P
m values. Concentrations from 140 to 180 μg/mL had the opposite effect. These results are consistent with previous reports
on the effects of rare earth elements on plant growth. We propose that the lanthanum-induced change of mitochondrial metabolic
activity is a possible mechanism by which La (III) ions influence indica rice 9311 growth. 相似文献
2.
Rare earth elements (REEs) have beneficial influence on plant growth and are widely used in agriculture practice, but little is known about behavior of the REEs on mitochondria in plant cells. Thermogenic metabolic curves were determined by the ampoule method at 303 K using a TAM air isothermal microcalorimeter in mitochondria isolated from indice rice 9311 (Oryza sativa L.), and the effect of Ce(III) on mitochondrial metabolism was investigated. By analyzing the obtained heat flux curves, the crucial parameters such as activity recovery rate constant (k) and maximum heat power (P(m)) were investigated. Application of Ce3+ in concentrations ranging from 0 to 120 microg/ml significantly increased k and P(m) values, with the maximum reaching 261 and 180% of the control, respectively. Concentrations from 140 to 150 microg/ml had the opposite effect. These results were consistent with previous reports on the effects of REEs on plant growth. It was concluded that the Ce(III)-induced change of mitochondrial metabolic activity is a possible mechanism by which Ce(III) influenced indice rice 9311 growth. 相似文献
3.
J. Yao Y. Liu Y. Tuo J. Zhu X. Qin J. Dong S. Qu Z. Yu 《Applied Biochemistry and Microbiology》2006,42(3):274-277
The metabolic power-times curves of Bacillus thuringiensis and its vegetative insecticidal protein-engineered strains were determined at 30°C using a thermal activity monitor, air
Isothermal Microcalorimeter, and ampoule method. From the power-times curves, the maximum power (P
max) in the log phase, growth rate constant (k), generation times (t
G), time of the maximum power (t
max), heat effects (Q
log) for log phase, and the total heat effect in 45 h (Q
total) of. B. thuringiensis strains can be obtained. The results indicate that their power-times curves are different. The relationship between their
metabolic power-times curves and character of bacteria metabolism, and thermokinetics and gene expression were analyzed and
discussed. The character of the bacteria power-times curves reflected the physiologic character of gene expression. The microcalorimetric
method proved to be a reliable and sensitive tool for the assessment of growth metabolism, heat output in bacteria and its
engineered strains. The determination of the thermokinetic character is beneficial to the control of fermentation.
The text was submitted by the authors in English. 相似文献
4.
The effect of cerium on mitochondria isolated from hybrid rice Shanyou 63 (Oryza sativa L) was investigated. Through in vivo culture, low dose Ce3+ promoted, but higher dose Ce3+, restrained mitochondrial heat production. However, through vitro incubation, Ce3+ showed only inhibitory action on mitochondrial energy turnover, the concentration required for 50% inhibition being 46.7 μM.
In addition, Ce3+, like Ca2+, induced rice mitochondrial swelling and decreased membrane potential (△ψ), which was inhibited by the specific permeability transition inhibitor cyclosporine A (CsA). The induction approached a
constant level while mitochondrial metabolism was fully prevented by Ce3+. These results demonstrated that cerium influenced rice mitochondria in vivo and in vitro via different action pathways,
and the latter involved the opening of rice mitochondrial permeability. 相似文献
5.
Peng L Yi L Zhixiong X Anxin H Ping S Songsheng Q 《Biological trace element research》2005,104(3):275-284
A microcalorimetric technique was used to evaluate the influence of Er3+ on Halobacterium halobium R1 growth. By means of a LKB-2277 Bioactivity Monitor ampoule method, we obtained the thermogenic curves of H. halobium R1 growth at 37°C. In order to analyze the results, the relationship between k and C was obtained. The addition of Er3+ in low concentration cause a decrease of the maximum heat production P
max and growth rate constants k; however, Er3+ in a high concentration might promote growth of H. halobium R1. When Er3+ is in a much higher concentration, the growth of H. halobium R1 is inhibited completely. For comparison, the shapes of H. halobium R1 cells were observed by means of transmission electron microscope (TEM). According to the thermogenic curves and TEM photos
of H. halobium R1 under different conditions, it is clear that the metabolic mechanism of H. halobium R1 growth has been changed with the addition of Er3+. 相似文献
6.
Chunying Chen Yi Liu Jinyan Zhou Huibi Xu Songsheng Qü 《Biological trace element research》1997,60(1-2):115-122
The metabolic thermograms and heat output of mitochondria isolated from carp liver have been determined by using an LKB bioactivity
monitor. The thermogram can be divided into four parts: the lag phase, active recovery phase, stationary phase, and decline
phase. The thermokinetic equation was established for the active recovery and decline phase of metabolism as follows: dP/dt
=k
mP (1-SP). The rate constantsk
1 andk
2 of two phases of active recovery and decline phase have been also calculated. The metabolism activity of mitochondrial inhibited
by a high concentration of trace element selenium has been studied. The metabolic heat released, time of each phase, and rate
constants can be significantly influenced by excess of selenite added. These results suggested that a high concentration of
selenium can damage the structure and function of mitochondria, and thus influence their metabolism. 相似文献
7.
In order to explore the role of mitochondria in proliferation promotion and/or apoptosis induction of lanthanum, the mutual
influences between La3+ and Ca2+ on mitochondrial permeability transition pore (PTP) opening were investigated with isolated mitochondria from rat liver.
The experimental results revealed that La3+ influence the state of mitochondria in a concentration-dependent biphasic manner. La3+ in nanomolar concentrations, acting as a Ca2+ analog, entered mitochondrial matrix via the RuR sensitive Ca2+ channel and elevated ROS level, leading to opening of PTP indicated by mitochondrial swelling, reduction of ΔΨm and cytochrome c release. Inhibition of PTP with 10 μM CsA attenuated the effects of La3+. However, micromolar concentrations La3+ acted mainly as a Ca2+ antagonist, inhibiting PTP opening induced by Ca2+. We postulated that this action of La3+ on mitochondria through interaction with Ca2+ might be involved in the proliferation-promoting and apoptosis induction by La3+. 相似文献
8.
I. V. Shemarova S. M. Korotkov V. P. Nesterov 《Journal of Evolutionary Biochemistry and Physiology》2013,49(4):423-428
The inotropic action of La3+ on frog myocardium was studied with taking into account its effect on mitochondria of cardiomyocytes (CM). It has been established that in the range of studied concentrations (0.2–6.0 mM), La3+ decreases dose-dependently the force of cardiac contractions (by 3.3–92.2%). In parallel experiments on isolated rat heart mitochondria (RHM), La3+ at a concentration of 25 μM has been shown to cause swelling of non-energized and energized mitochondria incubated in isotonic medium with 125 mM NH4NO3 and in hypotonic medium with 25 mM CH3COOK. The study of oxidative processes in mitochondria with aid of polarographic method of measurement of oxygen concentration has shown that La3+ at concentrations of 50 and 100 μM increases the oxygen consumption rate by mitochondria in the state 2. However, La3+ does not decrease the respiration rate of isolated mitochondria in the state 3, as this takes place in the case of use of Cd2+ or at the Ca2+-overloading of mitochondria. The rate of endogenous respiration of isolated mitochondria in the medium with La3+ was higher than in control, which suggests its effect on ion permeability of the inner membrane. The data obtained in this work indicate that the La3+-produced decrease of contractility of cardiac muscle is not only due to the direct blocking effect on the potential-controlled Ca2+-channels, but is also mediated by its unspecific action on the CM mitochondria. This action is manifested as an acceleration of the energy-dependent K+ transport in matrix and as an increase of ion permeability of the inner mitochondrial membrane (IMM). 相似文献
9.
Direct evidence for the presence of a rotenone-resistant NADH dehydrogenase on the inner surface of the inner membrane of plant mitochondria 总被引:2,自引:0,他引:2
Submitochondrial particles (SMP) were produced from Jerusalem artichoke (Helianthus tuberosus L.) mitochondria by sonication and differential centrifugation. The SMP were about 50% inside-out as measured by the access of reduced cytochrome c to cytochrome c oxidase. Uncoupled NADH oxidation (1 mM NADH) by the SMP was 120 nmol O2 min?1mg?1, which was reduced to 98 nmol O2 min?1 (mg mitochondrial protein)?1 in the presence of EGTA. In contrast, the oxidation of NADH by intact mitochondria was completely inhibited by EGTA (from 182 to 14 nmol O2 min?1mg?1). The EGTA-resistant NADH oxidation by the SMP is ascribed to the NADH dehydrogenase(s) on the inside of the inner membrane and exposed to the medium in the inside-out SMP. In the presence of EGTA it could be shown that two NADH dehydrogenase activities were present in the SMP. One had an apparent Km of 7 μM for NADH, a Vmax of 80 nmol NADH min?1mg?1, and was rotenone-sensitive. This dehydrogenase is equivalent to the mammalian Complex I NADH dehydrogenase. The other dehydrogenase, which was rotenone-resistant, had a Km of 80 μM and a Vmax of 131 nmol NADH min?1mg?1; it is probably responsible for the rotenone-resistant oxidation of organic acids often observed in plant mitochondria. The redox poise of the pyridine nucleotides had only a small effect on the relative rates of the two internal dehydrogenases. Electron flow through these dehydrogenases appears, therefore, to be regulated mainly by the concentration of NADH in the matrix of the mitochondria. 相似文献
10.
The biological effect of Ho3+ on Halobacterium halobium R1 growth was analyzed using the microcalorimetric method. Using the LKB-2277 Bioactivity Monitor with the ampoule method
at 37°C, the thermogenic curves of the growth of H. halobium R1 were obtained. Then, the maximum power (P
m) and the growth rate constants (k) were determined, and the values of P
m and k were linked to the concentration of Ho3+. In all, the addition of Ho3+ cause a decrease in the maximum heat production and growth rate constants. To confirm the results, the shapes of H. halobium R1 cell addition with Ho3+ using a transmission electron microscope (TEM) were observed. According to the thermogenic curves and TEM photos of H. halobium R1 under different conditions, it is clear that the metabolic mechanism of H. halobium R1 growth has been changed with the addition of Ho3+. 相似文献
11.
The toxic effect of Pb2+ has been studied in eukaryotic cells by using Tetrahymena as a target. The maximum power (P
m) and the growth rate constant (k) were determined, which showed that values of P
m and k were linked to the concentration (C) of Pb2+. The addition of Pb2+ caused a decrease of the maximum heat production and growth rate constant, indicating that Tetrahymena growth was inhibited in the presence of Pb2+, and Pb2+ took part in the metabolism of cells. From micrographs, morphological changes of Tetrahymena were observed with addition of Pb2+, indicating that the toxic effect of Pb2+ derived from destroying the membrane of surface of Tetrahymena. According to the thermogenic curves and photos of Tetrahymena under different conditions, it is clear that metabolic mechanism of Halobacterium halobium R1 growth has been changed with the addition of Pb2+. 相似文献
12.
The biological effect of Ho3+ on Halobacterium halobium R1 growth was analyzed by a microcalorimetric technique. By means of LKB-2277 Bioactivity Monitor, ampoule method at 37°C,
we obtained the thermogenic curves of H. halobium R1 growth. To analyze the results, the maximum power (P
m) and the growth rate constants (k) were determined, which show that values of P
m and k are linked to the concentration of Ho3+. In all, the addition of Ho3+ causes a decrease of the maximum heat production and growth rate constants. For comparison, we observed the shapes of H. halobium R1 cell by means of transmission electron microscope (TEM). According to the thermogenic curves and TEM photos of H. halobium R1 under different conditions, it is clear that metabolic mechanism of H. halobium R1 growth has been changed with the addition of Ho3+. 相似文献
13.
S. Saarela R. Hissa 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》1993,163(7):546-555
Wood lemmings (Myopus schisticolor) were captured during their autumnal migration in September and October. The animals were maintained at 12°C and under 12L:12D photoperiod. Basal metabolic rate and thermogenic capacity of the wood lemming were studied. Basal metabolic rate was 3.54 ml O2·g-1·h-1, which is 215–238% of the expected value. The high basal metabolic rate seems to be typical of rodents living in high latitudes. The body temperature of the wood lemming was high (38.0–38.8°C), and did not fluctuate much during the 24-h recording. The high basal metabolic rate and the high body temperature are discussed with regard to behavioural adaptation to a low-quality winter diet. Thermogenic capacity, thermal insulation and non-shivering thermogenesis of the wood lemming displayed higher values than expected: 53.0 mW·g-1, 0.53 mW·g-1·C-1 and 53.2 mW·g-1, respectively. Brown adipose tissue showed typical thermogenic properties, although its respiratory property was fairly low, but mitochondrial protein content was high compared to other small mammals. The 24-h recording of body temperature and motor activity did not reveal whether the wood lemming is a nocturnal animal. Possibly, the expression of a circadian rhythm was masked by peculiar feeding behaviour. It is concluded that the wood lemming is well adapted to living in cold-temperature climates.Abbreviations BAT
brown adipose tissue; bm, body mass
- BMR
basal metabolic rate
-
C
conductance
- Cox
cytochrome-c-oxidase
- HP
heat production
- HPmax
maximum heat production
-
M
metabolism
- NA
noradrenaline
- NST
non-shivering thermogenesis
- NSTmax
maximum non-shivering thermogenesis
- RMR
resting metabolic rate
- RQ
respiratory quotient
-
T
a
anibient temperature
-
T
b
body temperature
-
T
lc
lower critical temperature
- UCP
uncoupling protein
- vO2
oxygen consumption
- vO2 max
maximum oxygen consumption 相似文献
14.
Effects of rare earth elements on growth rate,lipids, fatty acids and pigments in microalgae
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Franz Goecke Milada Vítová Jaromír Lukavský Linda Nedbalová Tomáš Řezanka Vilém Zachleder 《Phycological Research》2017,65(3):226-234
The extensive exploitation of rare earth elements (REEs), particularly in electronic technologies and agriculture has concomitantly raised the environmental load. Their resulting effects on primary producers such as microalgae are, however, poorly understood. We have studied these effects on two microalgae of biotechnological interest. The yellow‐green alga Trachydiscus minutus (Eustigmatophyceae, Ochrophyta), and the green alga Parachlorella kessleri (Trebouxiophyceae, Chlorophyta) were cultivated in mineral medium supplemented with 10 μmol L?1 chlorides of REEs: cerium, gadolinium, lanthanum, lutetium, praseodymium, scandium, and with monazite, which is a mineral rich in those elements. We observed growth rates at different mean light intensities (20, 50, 150 and 300 μmol m?2 s?1). The high growth rate of P. kessleri was not affected by the presence of any lanthanide, and decreased proportionally with light intensity (from 0.2 to 0.04 doublings per hour). In contrast, the growth rate of T. minutus was about three times lower compared with P. kessleri, with an optimum at 50 μmol m?2 s?1 and decreased at higher or lower light intensities. In the presence of Ce3+, La3+ and Sc3+, the growth rate markedly increased to a value that corresponded to the growth rate in P. kessleri at the same light intensity. The composition and content of pigments and lipids were followed at the optimum light intensity for both species. The lipid content (percentage of dry weight) varied only slightly in the presence of individual rare earths. There was, however, an increase in saturated fatty acids at the expense of polyunsaturated fatty acids. The effect of REEs on pigments was variable: the presence of Ce3+, Gd3+, La3+ and Sc3+ caused an increase in the concentrations of major pigments such as lutein, violaxanthin, β‐carotene or chlorophylls, while Pr3+ and Lu3+ reduced them. 相似文献
15.
Ana Maria Andia-Waltenbaugh Charlotte A. Tate Naomi Kraus Friedmann 《Molecular and cellular biochemistry》1981,36(3):177-184
Summary Previous work by this and other laboratories has shown that glucagon administration stimulates calcium uptake by subsequently
isolated hepatic mitochondria. This stimulation of hepatic mitochondrial Ca2+ uptake byin vivo administration of glucagon was further characterized in the present report. Maximal stimulation of mitochondrial Ca2+ accumulation was achieved between 6–10 min after the intravenous injection of glucagon into intact rats. Under control conditions,
Ca2+ uptake was inhibited by the presence of Mg2+ in the incubation medium. Glucagon treatment, however, appeared to obliterate the observed inhibition by Mg2+ of mitochondrial Ca2+ uptake. Kinetic experiments revealed the usual sigmoidicity associated with initial velocity curves for mitochondrial calcium
uptake. Glucagon treatment did not alter this sigmoidal relationship. Glucagon treatment significantly increased the Vmax for Ca2+ uptake from 292±22 to 377±34 nmoles Ca2+ /min per mg protein (n=8) but did not affect the K0.5, (6.5–8.6 μM). Since the major kinetic change in mitochondrial Ca2+ uptake evoked by glucagon is an increase in Vmax, the enhancement mechanism is likely to be an increase either in the number of active transport sites available to Ca2+ or in the rate of Ca2+ carrier movement across the mitochondrial membranes. 相似文献
16.
The effect of Li(I) on the metabolism of mitochondria isolated from Carassius auratus liver tissue was investigated by microcalorimetric method to provide evidence for mitochondria hypothesis of biporlar disorder
(BPD) and to explore therapeutic mechanism of drug for treatment of BPD. Obvious stimulation induced by Li(I) on mitochondria
metabolism was reflected by power-time (P-t) curves. The power-time curves of hepatic mitochondria metabolism without Li(I) could be divided into four parts: lag phase,
active recovery phase, stationary phase, and decline phase. When Li(I) was added, the second heat peak occurred in a concentration-dependent
sequence. Considering the first heat peak on the p-t curves, Li(I) in the range of therapeutic and lower concentration induced slight alterations in comparison with the characteristic
heat peak observed in the control. However, Li(I) above the therapeutic concentration resulted in significant changes. Heat
output increased with the concentration of Li(I), but the rate constant (k
2) and the maximum heat power (P
max2) for the second heat peak reached maximum value in the range of therapeutic concentration. Mechanism of activation of mitoKatp
was suggested and discussed. 相似文献
17.
3-Methylcrotonyl-Coenzyme A Carboxylase Is a Component of the
Mitochondrial Leucine Catabolic Pathway in Plants 总被引:3,自引:1,他引:2
Marc D. Anderson Ping Che Jianping Song Basil J. Nikolau Eve Syrkin Wurtele 《Plant physiology》1998,118(4):1127-1138
3-Methylcrotonyl-coenzyme A carboxylase (MCCase) is a mitochondrial biotin-containing enzyme whose metabolic function is not well understood in plants. In soybean (Glycine max) seedlings the organ-specific and developmentally induced changes in MCCase expression are regulated by mechanisms that control the accumulation of MCCase mRNA and the activity of the enzyme. During soybean cotyledon development, when seed-storage proteins are degraded, leucine (Leu) accumulation peaks transiently at 8 d after planting. The coincidence between peak MCCase expression and the decline in Leu content provides correlative evidence that MCCase is involved in the mitochondrial catabolism of Leu. Direct evidence for this conclusion was obtained from radiotracer metabolic studies using extracts from isolated mitochondria. These experiments traced the metabolic fate of [U-14C]Leu and NaH14CO3, the latter of which was incorporated into methylglutaconyl-coenzyme A (CoA) via MCCase. These studies directly demonstrate that plant mitochondria can catabolize Leu via the following scheme: Leu → α-ketoisocaproate → isovaleryl-CoA → 3-methylcrotonyl-CoA → 3-methylglutaconyl-CoA → 3-hydroxy-3-methylglutaryl-CoA → acetoacetate + acetyl-CoA. These findings demonstrate for the first time, to our knowledge, that the enzymes responsible for Leu catabolism are present in plant mitochondria. We conclude that a primary metabolic role of MCCase in plants is the catabolism of Leu. 相似文献
18.
Birkedal R Gesser H 《Journal of comparative physiology. B, Biochemical, systemic, and environmental physiology》2004,174(3):255-262
In skinned rat cardiac fibres, mitochondrial affinity for endogenous ADP generated by creatine kinase and Ca2+-activated ATPases is higher than for exogenous ADP added to the surrounding medium, suggesting that mitochondria are functionally coupled to creatine kinase and ATPases. Such a coupling may be weaker or absent in ectothermic vertebrate cardiac cells, because they typically have less elaborate intracellular membrane structures, higher glycolytic capacity and lower working temperature. Therefore, we examined skinned cardiac fibres from rainbow trout at 10 °C. The apparent mitochondrial affinity for endogenous ADP was obtained by stimulation with ATP and recording of the release of ADP into the surrounding medium. The apparent affinity for endogenous ADP was much higher than for exogenous ADP suggesting a functional coupling between mitochondria and ATPases. The apparent affinity for exogenous ADP and ATP was increased by creatine or an increase in Ca2+-activity, which should increase intrafibrillar turnover of ATP to ADP. In conclusion, ADP seems to be channelled from creatine kinase and ATPases to mitochondria without being released to the surrounding medium. Thus, despite difference in structure, temperature and metabolic capacity, trout myocardium resembles that of rat with regard to the regulation of mitochondrial respiration.Abbreviations ACR acceptor control ratio - ANT adenine nucleotide translocase - KM ADP apparent mitochondrial affinity for ADP - KM ATP apparent mitochondrial affinity for ATP - LDH lactate dehydrogenase - VADP ADP-stimulated respiration rate - VADP max maximal ADP-stimulated respiration rate - VATP ATP-stimulated respiration rate - VATP max maximal ATP-stimulated respiration rate - V0 basal respiration rate in the absence of ADPCommunicated by G. Heldmaier 相似文献
19.
Yi L Peng L Fengjiao D Zhong C Cunxin W Songsheng Q 《Biological trace element research》2001,84(1-3):103-112
The thermogenic curves of the metabolism of mitochondria isolated from the liver of chicken Star-Cross 288 and the effect
of La3+ on it were studied by using an LKB-2277 BioActivity Monitor, ampoule method, at 37°C. After isolation from the chicken liver
tissue, mitochondria still have metabolic activity and can live for a long time by using the stored nutrients. From the thermogenic
curves, we obtained the thermokinetic equations under different condition. The kinetic study shows that La3+ has changed the metabolism completely. 相似文献
20.
Michael J. Behrenfeld Ondrej Prasil Marcel Babin Flavienne Bruyant 《Journal of phycology》2004,40(1):4-25
The photosynthesis‐irradiance (PE) relationship links indices of phytoplankton biomass (e.g. chl) to rates of primary production. The PE curve can be characterized by two variables: the light‐limited slope (αb) and the light‐saturated rate (Pbmax) of photosynthesis. Variability in PE curves can be separated into two categories: that associated with changes in the light saturation index, Ek (=Pbmax/αb) and that associated with parallel changes in αband Pbmax (i.e. no change in Ek). The former group we refer to as “Ek‐dependent” variability, and it results predominantly from photoacclimation (i.e. physiological adjustments in response to changing light). The latter group we refer to as “Ek‐independent” variability, and its physiological basis is unknown. Here, we provide the first review of the sporadic field and laboratory reports of Ek‐independent variability, and then from a stepwise analysis of potential mechanisms we propose that this important yet largely neglected phenomenon results from growth rate–dependent variability in the metabolic processing of photosynthetically generated reductants (and generally not from changes in the oxygen‐evolving PSII complexes). Specifically, we suggest that as growth rates decrease (e.g. due to nutrient stress), reductants are increasingly used for simple ATP generation through a fast (<1s) respiratory pathway that skips the carbon reduction cycle altogether and is undetected by standard PE methodologies. The proposed mechanism is consistent with the field and laboratory data and involves a simple new “twist” on established metabolic pathways. Our conclusions emphasize that simple reductants, not reduced carbon compounds, are the central currency of photoautotrophs. 相似文献