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1.
Marcos Roberto de Oliveira Max William Soares Oliveira Rodrigo Lorenzi Ricardo Fagundes da Rocha José Cláudio Fonseca Moreira 《Cell biology and toxicology》2009,25(6):545-560
There is a growing body of evidence showing that vitamin A induces toxic effects in several experimental models and in human beings. In the present work, we have investigated the effects of short-term vitamin A supplementation on the adult rat liver redox status. We have found that vitamin A at therapeutic doses induces a hepatic oxidative insult. Furthermore, we have observed increased antioxidant enzyme activity in the liver of vitamin-A-treated rats. Additionally, some mitochondrial dysfunction was found since superoxide anion production was increased in vitamin-A-treated rat liver submitochondrial particles, which may be the result of impaired mitochondrial electron transfer chain activity, as assessed here. We have also isolated rat liver mitochondria and challenged it with 75 μM CaCl2, a non-oxidant agent that is able to induce mitochondrial oxidative stress indirectly. We have found that mitochondria isolated from vitamin-A-treated rat liver are more sensitive to CaCl2 than control mitochondria regarding the redox status. Importantly, vitamin A seems to alter mitochondrial redox status independently of the participation of the mitochondrial permeability transition pore, which is activated by Ca2+ ions since cyclosporin A did not prevent the oxidative insult elicited by Ca2+ addition. Overall, we show here that mitochondria are a target of vitamin-A-associated toxicity also in vivo. 相似文献
2.
J L Borowitz 《Journal of cellular physiology》1967,69(3):311-319
Significantly more calcium per gram protein was found in a relatively pure granule fraction isolated from fresh bovine adrenal medulla than in predominantly mitochondrial fractions isolated from the same tissue. Sixty-four and 55% of the calcium associated with chromaffin granule and mitochondrial fractions, respectively, was released into the supernatant upon lowering the tonicity of the medium. The per cent calcium released by this procedure was significantly greater for granules than for mitochondria (p < 0.05). The amount of calcium per gram protein released into the supernatant also was greater in granule fractions than in mitochondrial fractions (p < 0.05). These data, coupled with a previous report that 10?3 M EDTA does not markedly decrease the calcium content of whole granules, indicate that the excess calcium of the granule fractions relative to the mitochondrial fractions is maintained within the particles of that fraction. The functional significance of the relatively large amount of calcium in chromaffin granules is not clear. The presence of 150 mM sodium chloride or potassium chloride decreases calcium binding by granule or mitochondrial fragments incubated in 2.2 mM calcium chloride in 0.2 M Tris, pH 7, by about 50%. EDTA, 10?3 M, removes all but a small residual of the calcium associated with the granule or mitochondrial fragments whereas lowering the concentration of Tris increases calcium binding to about the same extent in both these subcellular fractions. The calcium-binding properties of granule and mitochondrial fragments therefore appear to be quantitatively and qualitatively similar. Inhibition of catecholamine release by relatively high concentrations of sodium may be explained by competitive inhibition of calcium binding. Calcium binding by granule fragments decreases with an increase in hydrogen ion concentration. 相似文献
3.
Michael J. Devinney Latha M. Malaiyandi Olga Vergun Donald B. DeFranco Teresa G. Hastings Kirk E. Dineley 《Cell calcium》2009,45(5):447-455
Intracellular Zn2+ toxicity is associated with mitochondrial dysfunction. Zn2+ depolarizes mitochondria in assays using isolated organelles as well as cultured cells. Some reports suggest that Zn2+-induced depolarization results from the opening of the mitochondrial permeability transition pore (mPTP). For a more detailed analysis of this relationship, we compared Zn2+-induced depolarization with the effects of Ca2+ in single isolated rat liver mitochondria monitored with the potentiometric probe rhodamine 123. Consistent with previous work, we found that relatively low levels of Ca2+ caused rapid, complete and irreversible loss of mitochondrial membrane potential, an effect that was diminished by classic inhibitors of mPT, including high Mg2+, ADP and cyclosporine A. Zn2+ also depolarized mitochondria, but only at relatively high concentrations. Furthermore Zn2+-induced depolarization was slower, partial and sometimes reversible, and was not affected by inhibitors of mPT. We also compared the effects of Ca2+ and Zn2+ in a calcein-retention assay. Consistent with the well-documented ability of Ca2+ to induce mPT, we found that it caused rapid and substantial loss of matrix calcein. In contrast, calcein remained in Zn2+-treated mitochondria. Considered together, our results suggest that Ca2+ and Zn2+ depolarize mitochondria by considerably different mechanisms, that opening of the mPTP is not a direct consequence of Zn2+-induced depolarization, and that Zn2+ is not a particularly potent mitochondrial inhibitor. 相似文献
4.
1-Methyl-4-phenylpyridinium (MPP+) or 6-hydroxydopamine (6-OHDA) caused a nuclear damage, the mitochondrial membrane permeability changes, leading to the cytochrome c release and caspase-3 activation, the formation of reactive oxygen species and the depletion of GSH in PC12 cells. Nicardipine (a calcium channel blocker), EGTA (an extracellular calcium chelator), BAPTA-AM (a cell permeable calcium chelator) and calmodulin antagonists (W-7 and calmidazolium) attenuated the MPP+-induced mitochondrial damage and cell death. In contrast, the compounds did not reduce the toxicity of 6-OHDA. Treatment with MPP+ or 6-OHDA evoked the elevation of intracellular Ca2+ levels. Unlike cell injury, addition of nicardipine, BAPTA-AM and calmodulin antagonists prevented the elevation of intracellular Ca2+ levels due to both toxins. The results show that the MPP+-induced formation of the mitochondrial permeability transition seems to be mediated by elevation of intracellular Ca2+ levels and calmodulin action. In contrast, the 6-OHDA-induced cell death seems to be mediated by Ca2+-independent manner. 相似文献
5.
Mitochondrial malate dehydrogenase of watermelon cotyledons: Time course and mode of enzyme activity changes during germination 总被引:1,自引:1,他引:0
Summary Specific antibodies were prepared against the purified mitochondrial malate dehydrogenase (EC 1.1.1.37) from cotyledons of watermelon seedlings (Citrullus vulgaris Schrad.). The isoenzyme was assayed by means of quantitative radial immunodiffusion. Cotyledons of ungerminated seeds were found to contain mitochondrial MDH. During the first 4 days of germination the enzyme activity increased threefold finally contributing 16% to the total MDH activity extracted from cotyledon tissue. Isopycnic CsCl density centrifugation was used to investigate the mode of activity increase. After a four-day period of labelling with deuterium oxide and purification of the mitochondrial isoenzyme, a density shift of 0.021kgx1-1, accompanied by considerable band broadening of the enzyme profile was observed. These findings are evidence for the de novo synthesis of mitochondrial MDH and its relatively slow turnover in germinating seeds.Abbreviations mMDH
mitochondrial malate dehydrogenase
- D2O
deuterium oxide 相似文献
6.
Arginases have been found to be located on the external side of the inner mitochondrial membrane of chicken kidney and liver. Transamidinase has been detected within the liver mitochondrial matrix space. Arginases and transamidinase act upon two different intracellular arginine pools. Penetration of arginine into the matrix space occurs only in respring mitochondria and in the presence of anions such as acetate and phosphate; D-arginine, L-ornithine, D-'ornithine and L-lysine penetrate with the same modalities. L-Histidine penetrates only kidney mitochondria. Because of transamidinase compartmentation, the rate of creatine synthesis is influenced by the rate of penetration of arginine into the mitochondria. 相似文献
7.
C. Julou V. Contamine F. Sor M. Bolotin-Fukuhara 《Molecular & general genetics : MGG》1984,193(2):275-279
Summary Due to the absence of repetition of the rRNA genes in S. cerevisiae mitochondria, isolation of ribosomal mutants at the level of the rRNA genes is relatively easy in this system. We describe here a novel thermosensitive mutation, ts1297, localized by rho- deletion mapping in (or very close to) the sequence corresponding to the small ribosomal RNA (15S) gene. Defective mutations of the small rRNA have not been reported so far.In the mutant, the amount of 15S rRNA and of the small ribosomal subunit, 37S, is reduced. The quantity of the large ribosomal RNA (21S), directly extracted from mitochondria, appears normal. However, the large ribosomal subunit, 50S, seems to be fragile and could be recovered only in the presence of Ca2+ in place of Mg2+. The 50S particles seem to be completely degraded under normal conditions of extraction with Mg2+.The thermosensitive phenotype of the ts1297 mutant is suppressed by a nuclear mutation SU101. The SU101 mutation had been originally isolated as a suppressor of another mitochondrial mutation, ts902, which is located within the 21S rRNA gene.These results suggest that the mitochondrial mutations ts1297 and ts902 are both involved in the interaction of the large and small ribosomal subunits. 相似文献
8.
Summary Autoradiography was found to be a useful method for studying the function of mitochondria. It might provide means to investigate the mitochondrial ATP-ase activity. Applying this method, different problems of metal salt-techniques, firstly the aspecific reactions, can be eliminated. The incubation solution contained 3H-ATP at 100 c activity. The autoradiographic precipitate seems to appear on the membrane of the mitochondria and in the intracristal space. Atractylate treatment inhibits completely the permeation of 3H-ATP. So-called arreactive mitochondria with retained structure lacking of reaction-precipitate were found besides the mitochondria revealing pronounced activity. This might refer to the manifestation of a functional state. Experiments with P32 ATP may contributs to the more exact determination of original place of the enzyme. 相似文献
9.
Because mitochondrial dysfunction occurs relatively early in the course of nephrotoxicity associated with the aminoglycoside antibiotic, gentamicin, the acute in vitro effects of gentamicin on renal cortical mitochondrial respiration were studied. Gentamicin produced stimulation of State 4 rates and inhibition of State 3 and DNP-uncoupled rates with pyruvate-malate or succinate as substrates. The stimulation of State 4 respiration was not blocked by oligomycin. Both the stimulation of State 4 and inhibition of State 3 were profoundly dependent on the Na+ and K+ contents of the incubation medium, were potentiated by the presence of EDTA, and were reversed by Mg2+. These results suggested that gentamicin's effects on mitochondrial respiration were due to alterations in the interaction of Na+ and K+ with the inner mitochondrial membrane at Mg2+-sensitive sites. 相似文献
10.
11.
MULLINS Lj 《The Journal of general physiology》1959,42(4):817-829
The influx of Na+, K+, Rb+, and Cs+ into frog sartorius muscle has been followed. The results show that a maximum rate is found for K+, while Na+ and Cs+ penetrate much more slowly. Similar measurements with Ca++, Ba++, and Ra++ show that Ba++ penetrates at a rate somewhat greater than that of either Ca++ or Ra++. All these divalent cations, however, penetrate at rates much slower than do the alkali cations. The results obtained are discussed with reference to a model that has been developed to explain the different penetration rates for the alkali cations. 相似文献
12.
Igor A. Skulskii Margarita V. Savina Vadim V. Glasunov Nils-Erik L. Saris 《The Journal of membrane biology》1978,44(2):187-194
Summary The distribution of Tl+ between rat liver mitochondria and the medium was studied; millimolar or smaller concentrations of Tl+ were labeled with204Tl. The Tl+ distribution responded to transient diffusion potentials in a way that indicated electrophoretic movements of Tl+. The diffusion potentials were induced by efflux of K+ in response to addition of valinomycin to nonrespiring mitochondria suspended in a medium with low concentrations of K+ or by efflux of H+ induced by making the medium more alkaline in the presence of a protonophorous (proton-conducting) uncoupling agent. Changes in membrane potential induced by valinomycin were followed with the aid of safranine. Tl+ brought about collapse of the diffusion potential. It is concluded that Tl+ is able to penetrate the mitochondrial membrane electrophoretically. 相似文献
13.
Masini A Ceccarelli-Stanzani D Muscatello U 《Journal of bioenergetics and biomembranes》1983,15(4):217-234
A possible relationship between mitochondrial Mg2+ levels, structural configurations, and functional steady states has been studied in rat liver mitochondria. The results show that the concentration of mitochondrial Mg2+ in respiratory state 4 is definitely higher than in respiratory state 3. The metabolic transition from state 3 to state 4 and vice-versa is associated with reversible influx-efflux of about 10 nmol of Mg2+ per mg protein. The net uptake of this aliquot of Mg2+ is a necessary condition in order for the metabolic transition to state 4, both structurally and functionally, to occur. This process requires a threshold concentration of external Mg2+ greater than 5 mM. The phosphorylative mechanism does not appear to depend on the presence or absence of external Mg2+. The role of Mg2+ on the attainment and maintenance of the structural and functional steady state 4 seems to be correlated with its regulatory effect on the concentration of the mitochondrial Pi. 相似文献
14.
Shin Kikuchi Takafumi Ninomiya Takayuki Kohno Takashi Kojima Haruyuki Tatsumi 《Cell biology and toxicology》2018,34(2):93-107
Cobalt is a trace element that localizes in the human body as cobalamin, also known as vitamin B12. Excessive cobalt exposure induces a peripheral neuropathy, the mechanisms of which are yet to be elucidated. We investigated how cobalt may affect mitochondrial motility in primary cultures of rat dorsal root ganglion (DRG). We observed mitochondrial motility by time-lapse imaging after DsRed2 tagging via lentivirus, mitochondrial structure using transmission electron microscopy (TEM), and axonal swelling using immunocytochemical staining. The concentration of cobaltous ion (Co2+) required to significantly suppress mitochondrial motility is lower than that required to induce axonal swelling following a 24-h treatment. Exposure to relatively low concentrations of Co2+ for 48 h suppressed mitochondrial motility without leading to axonal swelling. TEM images indicated that Co2+ induces mitochondrial destruction. Our results show that destruction of the axonal mitochondria precedes the axonal degeneration induced by Co2+ exposure. 相似文献
15.
Uthayashanker R. Ezekiel Hans Peter Zassenhaus 《Molecular & general genetics : MGG》1993,240(3):414-418
We have found a cruciform cutting endonuclease in the yeast, Saccharomyces cerevisiae, which localizes to the mitochondria. This activity apparently is associated with the mitochondrial inner membrane since the activity is not released into solution by osmolysis, in contrast to the matrix enzyme, isocitrate dehydrogenase. The cruciform cutting activity appears to be encoded by CCE1. This gene has been shown to encode one of the major cruciform cutting endonucleases present in a yeast cell. In ccel strains, which lack CCE1 endonuclease activity, the mitochondrial cruciform cutting endonucleolytic activity is also absent. Since CCE1 is allelic to MGT1, a gene required for the highly biased transmission of petite mitochondrial DNA in crosses between + and hypersuppressive – cells, it seems likely that the CCE1 endonuclease functions within mitochondria. 相似文献
16.
The technical establishment of boar sperm cryopreservation is indispensable for effective breeding of the scarce Okinawan native Agu pig. The objective was to determine whether an artificial anticell death protein (PTD-FNK protein) was capable of improving the quality of cryopreserved Agu sperm. Ejaculated Agu sperm frozen in an extender supplemented with 0, 100, 200, 300, or 400 nm PTD-FNK protein was thawed, and mitochondrial integrity and other sperm characteristics were evaluated. Treatment with 300 nm PTD-FNK protein had the most beneficial effect (P < 0.05) on mitochondrial integrity (45-59%) and sperm motility (56-67%) after freezing-thawing. In particular, the proportion of post-thaw sperm with activated caspase-9 and -3 but not caspase-8 was markedly reduced among sperm frozen in the presence of PTD-FNK protein (P < 0.05), implying protection against apoptotic-cell death in response to mitochondrial damage. There were high levels of intracellular ATP (9.4-10.5 nmol/108 sperm) in post-thaw sperm treated with PTD-FNK protein, and the inhibitory effect of PTD-FNK protein on activation of caspases influenced the increase in the number of sperm with intact DNA (36-53%; P < 0.05). Furthermore, the addition of PTD-FNK protein to the freezing extender strongly preserved the ability of the sperm to penetrate to mature oocytes in all individuals (60-80%; P < 0.05). In conclusion, treatment with PTD-FNK protein in the freezing extender effectively improved post-thaw qualities of fragile Agu sperm through prevention of mitochondrial dysfunction leading to apoptotic-cell death during cryopreservation. 相似文献
17.
Senescence of attached bean leaves accelerated by sprays of silicone oil antitranspirants 总被引:1,自引:0,他引:1
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Neumann PM 《Plant physiology》1974,53(4):638-640
During an investigation into the use of oil emulsions in foliar sprays, it was found that silicone oil emulsions accelerated the senescence of the primary leaves of bean (Phaseolus vulgaris) plants. It was shown that accelerated senescence was not a result of the reduced transpiration rates found in silicone-sprayed leaves. Furthermore, the silicone oil emulsions did not induce leakiness in plant cell membranes. The senescence-enhancing effect seems to be connected with the ability of the silicone oil emulsions to penetrate into the leaf interior. 相似文献
18.
Xiaorui Shi Weiju Han Hiroshi Yamamoto Irina Omelchenko 《Free radical research》2013,47(12):1313-1325
This study investigated the distribution of nitric oxide (NO) within isolated outer hair cells (OHCs) from the cochlea, its relationship to mitochondria and its modulation of mitochondrial function. Using two fluorescent dyes—4,5-diaminofluorescein diacetate (DAF-2DA), which detects NO, and tetramethyl rhodamine methyl ester (TMRM+), a mitochondrial membrane potential dye—it was found that a relatively greater amount of the DAF fluorescence in OHCs co-localized with mitochondria in comparison to DAF fluorescence in the cytosole. This study also observed reduced mitochondrial membrane potential of OHCs and increased DAF fluorescence following exposure of the cells to noise (120 dB SPL for 4 h) and to an exogenous NO donor, NOC-7 (>350 nm). Antibody label for nitrotyrosine was also increased, indicating NO-related formation of peroxynitrite in both mitochrondria and the cytosol. The results suggest that NO may play an important physiological role in regulating OHC energy status and act as a potential agent in OHC pathology. 相似文献
19.
Pilar Calo-Mata Inmaculada Fernández-No José M. Gallardo 《Analytical biochemistry》2009,391(2):127-67
In this study, we infer the phylogenetic relationships within commercial shrimp using sequence data from a novel mitochondrial marker consisting of an approximately 530-bp region of the 16S ribosomal RNA (rRNA)/transfer RNA (tRNA)Val genes compared with two other mitochondrial genes: 16S rRNA and cytochrome c oxidase I (COI). All three mitochondrial markers were considerably AT rich, exhibiting values up to 78.2% for the species Penaeus monodon in the 16S rRNA/tRNAVal genes, notably higher than the average among other Malacostracan mitochondrial genomes. Unlike the 16S rRNA and COI genes, the 16S rRNA/tRNAVal marker evidenced that Parapenaeus is more closely related to Metapenaeus than to Solenocera, a result that seems to be more in agreement with the taxonomic status of these genera. To our knowledge, our study using the 16S rRNA/tRNAVal gene as a marker for phylogenetic analysis offers the first genetic evidence to confirm that Pleoticus muelleri and Solenocera agassizi constitute a separate group and that they are more related to each other than to genera belonging to the family Penaeidae. The 16S rRNA/tRNAVal region was also found to contain more variable sites (56%) than the other two regions studied (33.4% for the 16S rRNA region and 42.7% for the COI region). The presence of more variable sites in the 16S rRNA/tRNAVal marker allowed the interspecific differentiation of all 19 species examined. This is especially useful at the commercial level for the identification of a large number of shrimp species, particularly when the lack of morphological characteristics prevents their differentiation. 相似文献
20.
Here, we sequenced the complete mitochondrial genome of the red-spotted tokay gecko (Squamata: Gekkonidae). The genome is 16,590 bp in size. Its gene arrangement pattern was identical with that of black-spotted tokay gecko. We compared the mitochondrial genome of red-spotted tokay gecko with that of the black-spotted tokay gecko. Nucleotide sequence of the two whole mitochondrial genomes was 97.99% similar, and the relatively high similarity seems to indicate that they may be separated at the subspecies level. The information of mitochondrial genome comparison of the two morphological types of tokay gecko is discussed in detail. 相似文献