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1.
A. Corsi Paola Bargellini V. Gallucci 《Cellular and molecular life sciences : CMLS》1962,18(3):120-121
Riassunto In presenza di ATP o ADP o pirofosfato, in concentrazioni da 10–2 a 104
M, la solubilità della miosina aumenta notevolmente a bassa forza ionica. Il legame che si forma fra la miosina e i polifosfati è tale che solo una dialisi prolungata può allontanarli interamente. 相似文献
2.
J. Suko 《Cellular and molecular life sciences : CMLS》1973,29(4):396-398
Zusammenfassung Der Ca2+-Transport und die Ca2+-aktivierte ATP Hydrolyse (ATP extra Spaltung) durch Membranen des cardialen sarkoplasmatischen Retikulums zeigen die gleiche Temperaturabhängigkeit. Die Aktivierungsenergie der Ca2+-Aufnahme und der ATP extra Spaltung, gemessen bei Anwesenheit von Oxalat, beträgt 16.65±0.87 und 17.93±0.49 Kcal/Mol–1. 相似文献
3.
Synergistic effect of acute hypoxia on flow-induced release of ATP from cultured endothelial cells 总被引:4,自引:0,他引:4
Human umbilical vein endothelial cells (HUVECs) in primary cultures were perfused under normoxic or hypoxic conditions. These cells were stimulated twice for 3 min by increased flow (from 0.5 to 3.0 ml/min). Under hypoxic conditions the basal release of ATP was the same as under normoxic conditions, but during increased flow the release was greater (0.58±0.07>0.32±0.04 pmoles/ml/106 cells (+78%), for the first period of stimulation; 0.39±0.05>0.22±0.03 pmoles/ml/106 cells (+79%) for the second period). Further experiments with sequential increments in flow rate showed that under both normoxic and hypoxic conditions, a positive correlation existed between ATP release and the rate of flow but there was always more ATP released under hypoxic conditions regardless of the flow rate.HUVECs in secondary culture (second passage) were similarly stimulated. No differences were observed between normoxic and hypoxic conditions. In both cases, the quantity of ATP released during high flow (0.050±0.004 pmoles/ml/106 cells) was significantly smaller than the quantity of ATP released during low flow (0.09±0.01 pmoles/ml/106 cells).To conclude, since hypoxia alone did not affect ATP release, there appears to be a synergistic relationship between increased shear stress and hypoxia in the stimulation of ATP release from HUVECs. Moreover, the release of ATP under these conditions seems to be a property of highly differentiated endothelial cells. 相似文献
4.
M. Hüttemann V. Frank B. Kadenbach 《Cellular and molecular life sciences : CMLS》1999,55(11):1482-1490
A single cDNA of cytochrome c oxidase subunit VIa was characterised from liver, heart and the thermogenic organ of the partially
endotherm tuna fish. The amino acid sequence revealed high identity with subunit VIa from carp and trout, but low identity
to subunits VIaL (liver type) and VIaH (heart type) of mammalian cytochrome c oxidase. In reconstituted cytochrome c oxidase
from bovine heart, the H +/e− stoichiometry is decreased from 1.0 to 0.5 at high intraliposomal ATP/ADP ratios via exchange of bound ADP by ATP at the
matrix domain of the transmembraneous subunit VIaH. Reconstituted cytochrome c oxidase from bovine liver and kidney, containing
subunit VIaL, revealed H +/e− ratios below 0.5, independent of the ATP/ADP ratio. The results suggest the evolution of three types of subunit VIa. Subunits
VIaH and VIaL are postulated to participate in mammalian thermogenesis.
Received 3 May 1999; received after revision 10 June 1999; accepted 29 June 1999 相似文献
5.
Allometry of mammalian cellular oxygen consumption 总被引:3,自引:0,他引:3
R.K. Porter 《Cellular and molecular life sciences : CMLS》2001,58(5-6):815-822
In the 1930s, Max Kleiber and Samuel Brody established that the interspecies correlation between mammalian body mass and
metabolic rate (αM0.75) cannot be explained (solely) by whole body surface area (αM0.66) to volume ratios. Metabolic considerations must also be taken into account. Decreases in the proportion of visceral organ
mass to whole body mass can account for some of the whole body metabolic differences. However, superimposed upon these anatomical
differences, the metabolism of tissues and cells has been demonstrated to decrease with increasing body mass. These decreases
in oxygen consumption rates (with increasing body mass) in cells and tissues can be explained by a decrease in ATP turnover
and mitochondrial density and an increase in mitochondrial functional efficiency (decrease in proton leak). The majority of
the proton leak differences reflect differences in mitochondrial inner membrane surface area. Indeed, liver metabolism correlates
directly with liver mitochondrial inner membrane surface area. Apart from being a significant contributor (~25 %) to basal
metabolism, mitochondrial proton leak is a major factor determining the differences in basal metabolism between mammals of
different body mass.
Received 31 May 2000; received after revision 2 October 2000; accepted 14 November 2000 相似文献
6.
Alexander V. Zhdanov Ruslan I. Dmitriev Dmitri B. Papkovsky 《Cellular and molecular life sciences : CMLS》2011,68(5):903-917
Bafilomycin A1 (Baf) induces an elevation of cytosolic Ca2+ and acidification in neuronal cells via inhibition of the V-ATPase. Also, Baf uncouples mitochondria in differentiated PC12
(dPC12), dSH-SY5Y cells and cerebellar granule neurons, and markedly elevates their respiration. This respiratory response in dPC12 is accompanied by morphological changes in the mitochondria and decreases the mitochondrial pH, Ca2+ and ΔΨm. The response to Baf is regulated by cytosolic Ca2+ fluxes from the endoplasmic reticulum. Inhibition of permeability transition pore opening increases the depolarizing effect
of Baf on the ΔΨm. Baf induces stochastic flickering of the ΔΨm with a period of 20 ± 10 s. Under conditions of suppressed
ATP production by glycolysis, oxidative phosphorylation impaired by Baf does not provide cells with sufficient ATP levels.
Cells treated with Baf become more susceptible to excitation with KCl. Such mitochondrial uncoupling may play a role in a
number of (patho)physiological conditions induced by Baf. 相似文献
7.
J. A. Kiernan 《Cellular and molecular life sciences : CMLS》1972,28(6):653-655
Résumé Des suspensions de mastocytes péritoneaux isolées de rat furent incubées avec 10 substances différentes, connues ou presumées être des neurotransmitteurs. Seulement l'adenos ine triphosphate (ATP) aux concentrations supérieures à 2.64×10–6
M causèrent la dégranulation des mastocytes. L'ATP cause également la dégranulation des mastocytes dans le mésentère. L'action de l'ATP peut être responsible de la dégranulation des mastocytes cutanées observée après la stimulation antidromique des nerfs sensorieux, alors que de l'ATP est libéré dans la peau. 相似文献
8.
Summary Adenylate kinase activity of intact mitochondria is strongly inhibited by Ap5A, i.e.p
1,p
5-Di (adenosine-5-) pentaphosphate, whereas oxidative phosphorylation is not affected. Therefore, Ap5A is a useful tool to distinguish between oxidative and non oxidative ATP generating reactions.Acknowledgment. The generous support of Prof. Dr.Walther Lamprecht is gratefully acknowledged. J. L. thanks the Stipendienfonds des Verbandes der Chemische Industrie for a scholarship. 相似文献
9.
Summary Noradrenaline storing vesicles were isolated from the pig hypothalamus and incubated at 0° and 37 °C. In the presence of ATP the uptake of noradrenaline is activated by Mg++ but not by Ca++. At 37 °C the passive transport of noradrenaline is practically accomplished within 1 min, the active one within 6 min.
Ausgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft. 相似文献
Ausgeführt mit Unterstützung der Deutschen Forschungsgemeinschaft. 相似文献
10.
Summary The absorption of3H-digitoxin from perfused rat small intestine was inhibited by probenecid (1.0×10–2
M), ethacrynic acid (0.5×10–3
M), and mersalyl (8.0×10–3
M) indicating that digitoxin absorption is at least partly an active process. 相似文献
11.
Summary ATPases of the amine storing granules from bovine adrenal medulla and splenic nerves are inhibited by Tl+++ 3×10–5 and 5×10–6
M, respectively. Tl+ up to 10–3
M is ineffective. By T1+++ in concentrations of 10–4
M or more, proteins are precipitated, so that the enzyme inhibiton by these concentrations is unspecific. If T1+ is oxidized to Tl+++ in the organism, the inhibition of granular ATPase may be responsible for the alterations of the catecholamine metabolism observed in thallium intoxication. 相似文献
12.
Dhar-Chowdhury P Malester B Rajacic P Coetzee WA 《Cellular and molecular life sciences : CMLS》2007,64(23):3069-3083
Glycolysis is an evolutionary conserved metabolic pathway that provides small amounts of energy in the form of ATP when compared
to other pathways such as oxidative phosphorylation or fatty acid oxidation. The ATP levels inside metabolically active cells
are not constant and the local ATP level will depend on the site of production as well as the respective rates of ATP production,
diffusion and consumption. Membrane ion transporters (pumps, exchangers and channels) are located at sites distal to the major
sources of ATP formation (the mitochondria). We review evidence that the glycolytic complex is associated with membranes;
both at the plasmalemma and with membranes of the endo/sarcoplasmic reticular network. We examine the evidence for the concept
that many of the ion transporters are regulated preferentially by the glycolytic process. These include the Na+/K+-ATPase, the H+-ATPase, various types of Ca2+-ATPases, the Na+/H+ exchanger, the ATP-sensitive K+ channel, cation channels, Na+ channels, Ca2+ channels and other channels involved in intracellular Ca2+ homeostasis. Regulation of these pumps, exchangers and ion channels by the glycolytic process has important consequences
in a variety of physiological and pathophysiological processes, and a better understanding of this mode of regulation may
have important consequences for developing future strategies in combating disease and developing novel therapeutic approaches.
Received 20 July 2007; received after revision 30 July 2007; accepted 17 August 2007 相似文献
13.
A. Wüthrich H. J. Schatzmann P. Romero 《Cellular and molecular life sciences : CMLS》1979,35(12):1589-1590
Summary Ca2+ loaded inside-out vesicles from human red blood cells, yielding Ca2+ into a Ca2+ free medium with 4 mM EGTA, 2 mM ADP and 10 mM phosphate, produced an excess of 14.9 pmoles · min–1 · (mg protein)–1 of ATP compared to controls in which the transmembrane Ca2+ gradient was abolished by the ionophore A 23 187.We are obliged to Dr H. Fey and Miss H. Pfister (Veterinarybacteriological Institute Bern) and Dr H. Porzig (Pharmacological Institute Bern) for help and advice. 相似文献
14.
J. P. Issartel A. Dupuis J. Garin J. Lunardi L. Michel P. V. Vignais 《Cellular and molecular life sciences : CMLS》1992,48(4):351-362
The transmembrane electrochemical proton gradient generated by the redox systems of the respiratory chain in mitochondria and aerobic bacteria is utilized by proton translocating ATP synthases to catalyze the synthesis of ATP from ADP and Pi. The bacterial and mitochondrial H+-ATP synthases both consist of a membranous sector, F0, which forms a H+-channel, and an extramembranous sector, F1, which is responsible for catalysis. When detached from the membrane, the purified F1 sector functions mainly as an ATPase. In chloroplasts, the synthesis of ATP is also driven by a proton motive force, and the enzyme complex responsible for this synthesis is similar to the mitochondrial and bacterial ATP synthases. The synthesis of ATP by H+-ATP synthases proceeds without the formation of a phosphorylated enzyme intermediate, and involves co-operative interactions between the catalytic subunits. 相似文献
15.
Maria C. Shina Annette Müller-Taubenberger Can Ünal Michael Schleicher Michael Steinert Ludwig Eichinger Rolf Müller Rosemarie Blau-Wasser Gernot Glöckner Angelika A. Noegel 《Cellular and molecular life sciences : CMLS》2011,68(2):303-313
Dictyostelium discoideum harbors a short (CRN12) and a long coronin (CRN7) composed of one and two beta-propellers, respectively. They are primarily
present in the cell cortex and cells lacking CRN12 (corA
−) or CRN7 (corB
−) have defects in actin driven processes. We compared the characteristics of a mutant cell line (corA
−
/corB
−) lacking CRN12 and CRN7 with the single mutants focusing on cytokinesis, phagocytosis, chemotaxis and development. Cytokinesis,
uptake of small particles, and developmental defects were not enhanced in the corA
−
/corB
− strain as compared to the single mutants, whereas motility and phagocytosis of yeast particles were more severely impaired.
It appears that although both proteins affect the same processes they do not act in a redundant manner. Rather, they often
act antagonistically, which is in accordance with their proposed roles in the actin cytoskeleton where CRN12 acts in actin
disassembly whereas CRN7 stabilizes actin filaments and protects them from disassembly. 相似文献
16.
L. L. Sarliève F. V. DeFeudis L. Ossola P. Mandel 《Cellular and molecular life sciences : CMLS》1980,36(5):597-599
Summary Binding of [3H]GABA and [3H]muscimol, indicative of GABA-receptors, has been demonstrated in a neurone-enriched culture of embryonic mouse brain using a ligand-binding technique. Evidence is provided for the existence of different populations of GABA-receptors.This study was supported by C.N.R.S., ATP No 3356 and by Commissariat à l'Energie Atomique, Departement of Biologie. Thanks are due to Mlle Marie-Anne Frenkel for her excellent technical assistance. 相似文献
17.
Zusammenfassung Strychnin in einer Konzentration von 3×10–6 bis 3,5×10–5
M/l verursacht eine vorübergehende Vergrösserung derb-Welle des ERG der isolierten Kaninchennetzhaut, in einer Konzentration von 7×10–5 bis 7×10–4
M/l verkleinert es dieb-Welle. Aus den Ergebnissen wird geschlossen, dass die Substanz zumindest teilweise schon auf die Schicht des zweiten Neurons wirkt. 相似文献
18.
Summary DCP increases IAA destruction by bothLens andPhaseolus root breis. H2O2 inhibits catabolism byLens extracts but activates it whenPhaseolus is used, mainly when roots are cultivated in the dark and contain inhibitors of IAA destruction. DCP 1·10–3
M and H2O2 1·10–4 or 1·10–3 volume forLens and DCP 1·10–4
M and H2O2 1·10–3 volume forPhaseolus nullify auxin catabolism. 相似文献
19.
Pyrophosphate (PPi) is a non-hydrolyzable ATP analogue known to affect the binding between myosin heads and actin. By using a dynamic laser light scattering method, we have shown that 1–2 mM PPi enhances the increase in
values induced by Ca2+ in isolated thick myofilaments fromLimulus striated muscle. However, similar treatment has no effect on the
values of filaments suspended in either relaxing solution or ATP-free solution.
is the average linewidth of the photoelectron count autocorrelation function of the light scattered. PPi had no effect on the increase of
values by Sr2+ but it substantially increased the
values of the thick myofilaments suspended in Ba2+-substituted Ca2+ activating solution. The results show that PPi also affects the energy-requiring cyclic cross-bridge motions. 相似文献
20.
R. G. G. Andersson H. J. Arnqvist L. Lundholm 《Cellular and molecular life sciences : CMLS》1976,32(5):601-602
Summary The incorporation of leucice-14C into protein in bovine mesenteric arteries was augmented by cyclic GMP (10–3
M) and decreased by cyclic AMP (10–3
M). There was no effect of 5 AMP (10–3
M). The phosphodiesterase inhibiting drugs theophylline (10–3
M) and papaverine (5×10–5 g/ml) both decreased the leucine-14C incorporation.We are indebted to Mrs.Lena Burlin for hear assistance. Finacial support has been provided by the Swedish State Medical Research Council (No. 04X-101X-4498). 相似文献