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1.
Callus cultures were established from seedling root tips of mungbean (Vigna radiata (L.) Wilczek var. radiata) cv. K 851. The growing calli were exposed to increasing concentrations of thioproline — an analog of proline, in the medium. A concentration of 3.0 mM thioproline completely inhibited the growth of the cells. However, after 25 days incubation 5 cell clones were obtained which could grow on this concentration of thioproline. Out of them one vigorously growing cell clone was further characterized. This selected clone contained higher endogenous levels of free proline (5 fold) and K+ (1.5 fold) and exhibited elevated tolerance, not only to thioproline but also to exogenously applied NaCl in the growth medium, as compared to the normal sensitive callus cells. Higher endogenous levels of free proline and K+ appear to impart dual resistance to thioproline and NaCl to the selected cell strain. 相似文献
2.
Gilvano Ebling Brondani Heron Wilhelmus de Wit Ondas Francisco José Benedini Baccarin Antonio Natal Gon?alves Marcilio de Almeida 《In vitro cellular & developmental biology. Plant》2012,48(5):478-487
Eucalyptus benthamii is an important component of forestry plantations in cold regions, but it is difficult to obtain clonal plants of this species, especially by low rooting. In this study, we developed a method for cloning selected genotypes of E. benthamii using a micropropagation technique, enabling the formation of a clonal micro-garden. Nodal segments from sprouts of mini-stumps in the clonal mini-garden were used as explants. After in vitro establishment of the explants, we tested two selected clones (BP101 and BP118), three culture media (Wood Plant Medium (WPM), Correia and colleagues JADS medium, and Murashige and Skoog medium), and two plant growth regulators (6-benzylaminopurine (BAP) and ??-naphthaleneacetic acid (NAA)) for the multiplication of adventitious buds. Additionally, combinations of two other plant growth regulators (BAP and gibberellic acid (GA3)) were tested for the elongation of shoots. The in vitro and ex vitro rooting of micro-plantlets prior to acclimatization were compared. The in vitro bud multiplication of E. benthamii depended on the clone, culture medium, and concentration of plant growth regulators. The best results were obtained with WPM supplemented with 0.5?mg?L?1 BAP and 0.05?mg?L?1 NAA. The elongation of shoots depended on the clone and plant growth regulator, and the best results were obtained with nutrient medium free of GA3 and BAP. Histological analysis showed that both in vitro and ex vitro rooting were successful, resulting in normal development of adventitious roots showing a vascular connection with the vascular cambium. The new protocol is efficient for micro-plantlet production of E. benthamii and can be used for the formation of a clonal micro-garden for other Eucalyptus or tree species. 相似文献
3.
Callus production from willow (Salix viminalis L.) protoplasts 总被引:2,自引:0,他引:2
Protoplasts were isolated from cell suspensions of Salix viminalis (basket willow) clone 78-0-90 and S. schwerinii clone 77-0-77, using cellulysin and macerase in modified Woody Plant medium. For clone 78-0-90, 6.3 · 106 ± 1.9 · 106 protoplasts were obtained per gram fresh weight. Cell divisions started two days after protoplast isolation and gave rise to callus which has been maintained in culture for up to four years. Protoplast yield from the clone 77-0-77 was lower (less than 106 protoplasts per gram cells), cell division was infrequent and no callus was obtained. Protoplasts were also isolated from the leaves of willow shoot cultures using cellulysin and pectolyase, but these did not show cell divisions.Abbreviations BA
benzyladenine
- 2,4-D
2,4-dichlorophenoxyacetic acid
- MS medium
Murashige & Skoog (1962) medium
- WP medium
Woody Plant medium (Lloyd & McCown 1981) 相似文献
4.
This experiment is designed to determine the most suitable conditions and media for propagating three selected fig (Ficus carica L.) clones through tissue culture. The clone 37 displayed a higher performance than clones 50 and 82. As the multiplication
medium, the Murashige and Skoog (MS) medium containing 1 mg dm−3 α-indole-3-butyric acid (IBA), 1 mg dm−3 gibberellic acid and 5 mg dm−3 6-benzyladenine were the best, whereas, MS medium complemented with 1.2 and 2.5 μM IBA or 1-naphthalene acetic acid (NAA)
were better in respect to rooting. Peat followed by volcanic tuff gave the best performance for acclimatization to outdoor
conditions. 相似文献
5.
Endosulfan tolerant lines of mustard (Brassica campestris cv. Brown Sarson) have been developed through tissue culture methods. Cotyledonary expiants excised from eight day old in vitro grown seedlings were used for inducing callus. Fast growing friable callus was then transferred to MS medium containing (0.1–2.0 ugl–1) endosulfan for selection. Five alternating exposures with and without endosulfan containing medium yielded an endosulfan tolerant cell line (ETL). The plants regenerated from ETL were found to tolerate three fold higher concentrations of endosulfan. Callus induced from randomly selected endosulfan tolerant regenerated plants were also tolerant to 3.0 ugl endosulfan, thereby, suggesting that tolerance has been acquired at the gene level.Biochemical investigation revealed higher levels of total free sugar, free amino acids, protein and activity of peroxidase in the tolerant cell line.Abbreviations MS
Murashige and Skoog medium (1962)
- NSM
non-selective medium
- SM
selective medium
- BAP
6-Benzylaminopurine
- NAA
-naphthaleneacetic acid
- Z
zeatin 相似文献
6.
Shu-Qiu Wang Xiao-Jie Li Hong-Bin Qiu Zhi-Mei Jiang Maria Simon Xiao-Ru Ma Lei Liu Jun-Xing Liu Fang-Fang Wang Yan-Feng Liang Jia-Mei Wu Wei-Hua Di Shaobo Zhou 《PloS one》2014,9(7)
Purpose
To investigate the mechanism of the anti-epileptic effect of Ganoderma lucidum polysaccharides (GLP), the changes of intracellular calcium and CaMK II α expression in a model of epileptic neurons were investigated.Method
Primary hippocampal neurons were divided into: 1) Control group, neurons were cultured with Neurobasal medium, for 3 hours; 2) Model group I: neurons were incubated with Mg2+ free medium for 3 hours; 3) Model group II: neurons were incubated with Mg2+ free medium for 3 hours then cultured with the normal medium for a further 3 hours; 4) GLP group I: neurons were incubated with Mg2+ free medium containing GLP (0.375 mg/ml) for 3 hours; 5) GLP group II: neurons were incubated with Mg2+ free medium for 3 hours then cultured with a normal culture medium containing GLP for a further 3 hours. The CaMK II α protein expression was assessed by Western-blot. Ca2+ turnover in neurons was assessed using Fluo-3/AM which was added into the replacement medium and Ca2+ turnover was observed under a laser scanning confocal microscope.Results
The CaMK II α expression in the model groups was less than in the control groups, however, in the GLP groups, it was higher than that observed in the model group. Ca2 + fluorescence intensity in GLP group I was significantly lower than that in model group I after 30 seconds, while in GLP group II, it was reduced significantly compared to model group II after 5 minutes.Conclusion
GLP may inhibit calcium overload and promote CaMK II α expression to protect epileptic neurons. 相似文献7.
Gideon W. Schaeffer Frank T. Sharpe Jr. 《In vitro cellular & developmental biology. Plant》1981,17(4):345-352
Summary Rice cells derived from PI 353705 (similar to Assam 5) were isolated from anthers cultured on Blaydes medium containing IAA,
2,4-D, kinetin, yeast extract, and coconut milk. Isolated aggregates of cells were plated on a modified Blaydes medium containing
10−3
M S-aminoethyl-l-cysteine (S-AEC). This level ofS-AEC inhibits nonselected wild type cells. Cells or aggregates of cells resistant to this analog of lysine were subcultured
three times in the presence of 2×10−3
M S-AEC. The selected cells were then placed on a Murashige-Skoog (MS) regenerating medium containing 1 mg/l each of IAA and
kinetin. Ten plants were recovered from 34 selected cell lines, three plants grew to maturity, and two produced seeds. Seeds
from plants regenerated from cells in culture had higher lysine than the original field controls and had increased levels
of free alanine, arginine, and asparagine. The in vitro selection produced plants with higher protein than the field controls.
Plant breeders have begun to evaluate the genotype recovered from in vitro selection. 相似文献
8.
Naoki Goshima Toshihiro Mukai Mamiko Suemori Misa Takahashi Michel Caboche Hiromichi Morikawa 《The Plant journal : for cell and molecular biology》1999,19(1):75-80
The emission of N2 and N2O from intact transgenic tobacco (clone 271) expressing antisense nitrite reductase (NiR) mRNA, and wild-type plants grown aseptically, on NO3–, NO2– or NH4+ -containing medium was investigated. 15N contents of gas sampled from gas-sealed pots, in which the plants were grown on 15N-containing medium, were analyzed by gas chromato- graphy and mass spectrometry (GC–MS). No emission of N2 was detected in either of the gas samples from plant clone 271 or the wild-type grown on NO3–-containing medium. N2O emission from clone 271 grown on NO3–-containing medium was detected, but not from the wild-type plants. The N2O emission rate of clone 271 was 106 ng N2O mg–1 incorporated N week–1 and the N2O emission was inhibited by tungstate (a nitrate reductase inhibitor). No emission of N2O was found from clone 271 or wild-type plants grown on medium containing NH4+. Emission of N2O also was detected from clone 271 grown on NO2–-containing medium and its emission rate increased with increasing NO2– levels in plants. We speculate that NO3– is reduced to NO2– and that a part of NO2– is metabolized to N2O in clone 271. 相似文献
9.
When guinea pig spermatozoa are preincubated for 1 hr in Ca2+?free medium containing a low concentration of lysolecithin (LC, 85 μg/ml) and then exposed to 2 mM Ca2+ by diluting the preincubation medium with an equal volume of LC?free, 4 mM Ca2+?containing medium, the majority of the spermatozoa undergo acrosome reaction promptly. On the other hand, when the preincubated spermatozoa are exposed to 2 mM Ca2+ without reducing the original concentration of LC in the medium, none of them undergo acrosome reaction. These spermatoza can acrosome?react if they are transferred to an LC?free medium. These results and those of some other experiments suggest that in the presistent presence of a high concentration of LC in the medium, exogenous Ca2+ essential for the acrosome reaction either does not penetrate the sperm plasma membrane or, if it does, it cannot alter the membrane for the acrosome reaction, at least under the experimental conditions employed. Freeze?fracture examination of the sperm plasma membrane has revealed that small areas or patches free of intramembranous paarticles (IMPs) appear in the membrance during sperm preincubation, and these IMP?free areas expand drastically in response to Ca2+ when the LC conccentration in the medium is reduced at the time Ca2+ is added to the medium. In contrast, IMP?free areas remain unchanged even after exposure of spermatozoa to Ca2+ if the concentration of LC remains at its original level of 85 μg/ml. 相似文献
10.
Abstract Individual leaves and stems were analysed for Na+, Cl?, K+ and water content in two clones of Agrostis stolonifera differing in salt resistance, during 14 d of treatment with NaCl, 100 and 200 mol m?3, and a further 7 d in a salt-free medium. Great differences in ion and water content were revealed between individual organs, and organ-by-organ analysis also emphasized the differences between the clones better than whole shoot analysis. In both clones, Na+ and Cl? accumulated to the greatest degree in the older leaves, but for corresponding organs, the concentrations were lower in the more tolerant clone. In the sensitive clone, the lowest leaves dehydrated in 200 mol m?3 NaCl and failed to recover, while the plants of the more resistant clone maintained viable water content in all organs. In the resistant clone, K+ concentration decreased less in response to salt treatment than in the more sensitive clone. For a full appreciation of the plants' reactions, it was found necessary to express the analytical data on several bases, namely, per unit dry-weight, unit water, and total ion-content. 相似文献
11.
C. Kaendler M. Fladung H. Uhrig 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1996,92(3-4):455-462
A successful hybridization of a diploid clone of Solanum tuberosum with a rolC-transgenic, diploid S. papita clone is reported. By using leaf expiants of this S. papita clone, which after transformation expressed kanamycin resistance, intact protoplasts were obtained, but these protoplasts did not develop to microcalli or regenerate to mature plants. However, protoplasts of the S. tuberosum clone showed a high capacity to regenerate plants from isolated protoplasts. On a medium containing Kanamycin only calli regenerated to plants, which revealed a rolC phenotype (reduced apical dominance with a large number of adventitious shoots and a pale green color of leaves) and later on turned out to be true hybrids. Self fusions of S. papita never developed to microcalli and those of S. tuberosum ceased to develop on the kanamycin-containing medium. Identification of somatic hybrids was done by RFLP and RAPD analysis. In the greenhouse, out of four selected hybrids only FK3.1 was successfully crossed with two standard S. tuberosum varieties (Datura, Desirée). Out of all the seeds germinated, only rolC-negative F1 seedlings were further characterized. Within the seedling population obvious differences were evident in respect of the S. papita and S. tuberosum characteristics. 相似文献
12.
Shu-Qiu Wang Xiao-Jie Li Shaobo Zhou Di-Xiang Sun Hui Wang Peng-Fei Cheng Xiao-Ru Ma Lei Liu Jun-Xing Liu Fang-Fang Wang Yan-Feng Liang Jia-Mei Wu 《PloS one》2013,8(4)
Epilepsy can cause cerebral transient dysfunctions. Ganoderma lucidum spores (GLS), a traditional Chinese medicinal herb, has shown some antiepileptic effects in our previous studies. This was the first study of the effects of GLS on cultured primary hippocampal neurons, treated with Mg2+ free medium. This in vitro model of epileptiform discharge hippocampal neurons allowed us to investigate the anti-epileptic effects and mechanism of GLS activity. Primary hippocampal neurons from <1 day old rats were cultured and their morphologies observed under fluorescence microscope. Neurons were confirmed by immunofluorescent staining of neuron specific enolase (NSE). Sterile method for GLS generation was investigated and serial dilutions of GLS were used to test the maximum non-toxic concentration of GLS on hippocampal neurons. The optimized concentration of GLS of 0.122 mg/ml was identified and used for subsequent analysis. Using the in vitro model, hippocampal neurons were divided into 4 groups for subsequent treatment i) control, ii) model (incubated with Mg2+ free medium for 3 hours), iii) GLS group I (incubated with Mg2+ free medium containing GLS for 3 hours and replaced with normal medium and incubated for 6 hours) and iv) GLS group II (neurons incubated with Mg2+ free medium for 3 hours then replaced with a normal medium containing GLS for 6 hours). Neurotrophin-4 and N-Cadherin protein expression were detected using Western blot. The results showed that the number of normal hippocampal neurons increased and the morphologies of hippocampal neurons were well preserved after GLS treatment. Furthermore, the expression of neurotrophin-4 was significantly increased while the expression of N-Cadherin was decreased in the GLS treated group compared with the model group. This data indicates that GLS may protect hippocampal neurons by promoting neurotrophin-4 expression and inhibiting N-Cadherin expression. 相似文献
13.
M. Bonfill S. Bentebibel E. Moyano J. Palazón R. M. Cusidó R. Eibl M. T. Piñol 《Biologia Plantarum》2007,51(4):647-652
The effects of 100 and 200 μM methyl jasmonate (MJA) on cell proliferation and paclitaxel and baccatin III production were
investigated in free and alginate immobilized cells of Taxus baccata growing in a selected product formation culture medium. The greatest accumulation of paclitaxel (13.20 mg dm−3) and baccatin III (4.62 mg dm−3) occurred when 100 μM MJA was added to the culture medium of cells entrapped using a 1.5 and 2.5 % alginate solution. The
effects of different treatments on the viability of cultured cells and their capacity to excrete both taxanes into the surrounding
medium were considered. 相似文献
14.
Summary Cells of a non-nitrogen-fixing, drug-sensitive Enterobacter cloacae strain, isolated from the rhizosphere of Festuca heterophylla, were mated to Escherichia coli cells harboring plasmid pRD1. This plasmid carries the nitrogen-fixation (nif+) genes as well as three markers of drug resistance. After mating, triple-resistant Enterobacter transferants could be selected. These were screened for plasmids, acetylene reduction, and stability of the transferred markers.Transferants contained plasmid pRD1. Of 48, 43 were acetylene-reducing and therefore carried the nif+ genes. Triple-resistance was stable upon passage in liquid minimal medium, but the number of cells with nif+ genes decreased. Both the triple-resistant and the nif+ genotypes decreased in complete medium, although by different rates, depending on the particular line. The most stable line, M14, was chosen and checked further.Samples taken after 8–14 passages in minimal medium contained cells with different genotypes, plasmid sizes smaller than the original plasmid pRD1 and no free plasmids. Progeny of the latter cells, in addition to being triple-resistant, were the best acetylene reducers. It is concluded that in these cells the plasmid pRD1 with all its relevant genes had become integrated into the recipients' chromosome.Grass seedlings were inoculated with the bacteria containing integrated plasmid pRD1. They were then planted into pots with sterile ash and watered with a nutrient salt solution of limited nitrogen content. Sampling after 8 weeks showed that the inoculated bacteria were preserved, as demonstrated by their triple-resistance. They could also still fix nitrogen. 相似文献
15.
Molecular and in situ hybridization studies have shown, in a number of cell types, that under hypoxic conditions, vascular endothelial growth factor (VEGF) mRNA expression is up-regulated and VEGF protein is concomitantly increased. To establish a quantitative relationship between VEGF protein levels and oxygenation, we exposed exponentially growing clone A or HCT-8 human colon tumour cells in vitro (22 h at 37°C) to oxygen concentrations from 21% (air mixture) to 0.01%. Protein levels in cells and medium were then assayed using an enzyme-linked immunoabsorbent assay (ELISA). Intracellular levels of VEGF in clone A or HCT-8 cells exposed to either air (21% O2) or the 0.01% O2 mixture respectively increased from about 73 to 1270, and 1.5 to 1180 pg/106 cells (about 17- and 80-fold increases). The shapes of the response curves (log of the intracellular VEGF concentrations v. log oxygen concentration) for both cell types were sigmoidal. However, intracellular VEGF levels in HCT-8 cells were always less than that of clone A cells until levels of about 0.3 to 0.1% O2 were reached. Levels of VEGF in the supernatant were also increased after the 22 h hypoxic exposures. Because cell proliferation and clonogenicity were also measured, it was possible to estimate the secretion rates of VEGF for both cell lines as a function of oxygen percentage. For clone A cells, the secretion rate (pg/106 cells/h) in 21% O2 was 62.5. This rate increased to 428.8 pg/106 cells/h at 0.01% O2, a 7-fold increase. For HCT-8 cells, levels in the medium at 21% O2 were too low to be measured by ELISA. However, between 10% and 0.01% O2, secretion rates increased from 5.0 to 376.0 pg/106 cells/h, a 75-fold increase. Therefore, at very low O2 levels, VEGF secretion rates were similar in the two cell lines. We propose that the different VEGF responses of clone A and HCT-8 colon tumour cells to hypoxic stress in vitro are related to the in vivo observation that the respective hypoxic percentages of solid neoplasms originating from these cell lines are markedly different (i.e. about 3 versus 80%) at equivalent volumes of 750 mm3. 相似文献
16.
Serum-free production of recombinant proteins and adenoviral vectors by 293SF-3F6 cells 总被引:2,自引:0,他引:2
This article describes the step-wise approach undertaken to select a serum-free medium (SFM) for the efficient production of a recombinant adenoviral vectors expressing beta-galactosidase (Ad5 CMV-LacZ), in the complementing human embryonic kidney 293S cells. In the first step, a 293S-derived transfectoma, secreting a soluble epidermal growth factor receptor sEGFr (D2-22), was used to estimate the potential of selected serum-free formulations to support the production of a recombinant protein as compared to serum-containing medium. Assays showed that only one among six commercial serum-free formulations could support both sEGFr production and cell growth in static or suspension culture. In commercially available calcium-containing serum-free formulations, the cell aggregates reached up to 3 mm in diameter. In the second step, 293S cells were gradually adapted to a low-calcium version of the selected medium (LC-SFM). Cells were cloned, then screened according to their ability to grow at a rate and an extent comparable to parental cells in serum-containing medium (standard) as single cells or small aggregates. The 293SF-3F6 clone, first adapted to and then cloned in the selected serum-free medium, was selected for further experiments. Bioreactor run performed with the 293SF-3F6 clone showed similar growth curve as in the shake-flask controls. In the final step, the recombinant viral vector productivity of the 293S cells and the 293SF-3F6 clone was tested. The 293SF-3F6 cells infected by Ad5 CMV-LacZ in 3 L-scale bioreactor maintained the specific productivities of both beta-galactosidase and adenoviral vector equivalent to the shake-flask controls in suspension culture. Results from this study clearly demonstrate that the 293SF-3F6 cell line thus selected may be used either for establishing stable transfected cell line or for the production of adenoviral vectors required for gene therapy studies. 相似文献
17.
The disease resistance response in pea is associated with increased levels of specific mRNAs 总被引:1,自引:1,他引:0
A cDNA library was constructed using poly(A)+RNA fromPisum sativum which had been treated for 8 h with the fungusFusarium solani f. sp.phaseoli. Two thousand four hundred recombinant colonies were screened by differential colony hybridization using32P-labelled cDNAs prepared from RNA extracted from either noninoculated or inoculated pea tissue. cDNA clones were then selected,
which showed greater hybridization with cDNA prepared from pea RNA 8 h post-inoculation than with a cDNA probe from 0 h. Seven
distinct hybridization classes were chosen for further study. Northern blot analyses of total cellular RNAs inoculated for
16 h with eitherF. solani phaseoli or water demonstrated that each cDNA clone selected represents an mRNA species which increases substantially in abundance
during infection.
Results of3H-uridine pulse-labelling experiments suggested that enhanced synthesis is at least partially responsible for the accumulation
of the fungus-inducible mRNAs which hybridized with the clones. 相似文献
18.
In clone 707 of the Friend virus-induced erythroleukaemic cell line less than 1% of the cells stain detectably for haemoglobin with benzidine. On treatment with 2% dimethylsulphoxide (DMSO) the fraction of staining cells increases to 70–80%. Line Fw has a similar origin but does not respond to DMSO although up to 7–8% of these cells stain for haemoglobin when they are grown in intraperitoneal perfusion chambers. Evidence is presented that clone 707 does not contain sub-populations of non-inducible cells nor does the Fw line contain a sub-population of inducible cells. A BUdR-resistant derivative of clone 707, designated clone 707B2/7, was isolated and shown to be incapable of incorporating 3H-thymidine. A thioguanine-resistant derivative of line Fw, designated clone FwT6/4, was also isolated and shown to be incapable of incorporating 3H-hypoxanthine. Hybrids were prepared by fusing cells of clone 707B2/7 and clone FwT6/4 in the presence of inactivated Sendai virus and selecting the hybrids in HAT medium. The properties of parental and hybrid cells were studied. The hybrids contain chromosomes from both parents and can be induced with DMSO to form an increased fraction of haemoglobinized cells. 相似文献
19.
From a re-evaluation of experiments with the coccolithophorid Coccolithus hurleyi made by Paasche (1964), curves are presented showing the rate of photosynthesis as a function of the concentration of both free CO2 and bicarbonate CO2. It is shown that photosynthesis in a naked clone is due only to the uptake of free CO2. The problem concerning the high concentration of free CO2 necessary for photosynthesis in Coccolithus huxleyi is discussed. It is shown that it is not due to lack of the enzyme carbonic anhydrase. Hence it is probable that the formation of coccoliths is the mechanism by which, in Coccolithus, the utilization of HCO3- ions in photosynthesis becomes possible. The OH- ions produced during photosynthesis (+Ca2+ taken up together with the HCO3- ions) are thus neutralized. This situation is different from other aquatics utilizing HCO3- in photosynthesis. Here the OH- ions are neutralized via an ion exchange of Ca2+ with H+ in the surrounding medium. 相似文献
20.
Ian M. C. Dixon Masanori Kaneko Tomoji Hata Vincenzo Panagia Naranjan S. Dhalla 《Molecular and cellular biochemistry》1990,99(2):125-133
Although cardiac dysfunction due to ischemia-reperfusion injury is considered to involve oxygen free radicals, the exact manner by which this oxidative stress affects the myocardium is not clear. As the occurrence of intracellular Ca2+ overload has been shown to play a critical role in the genesis of cellular damage due to ischemia-reperfusion, this study was undertaken to examine whether oxygen free radicals are involved in altering the sarcolemmal Ca2+-transport activities due to reperfusion injury. When isolated rat hearts were made globally ischemic for 30 min and then reperfused for 5 min, the Ca2+ -pump and Na+-Ca2+ exchange activities were depressed in the purified sarcolemmal fraction; these alterations were prevented when a free radical scavenger enzymes (superoxide dismutase plus catalase) were added to the reperfusion medium. Both the Ca2+- pump and Na+- Ca2+ exchange activities in control heart sarcolemmal preparations were depressed by activated oxygen-generating systems containing xanthine plus xanthine oxidase and H2O2; these changes were prevented by the inclusion of superoxide dismutase and catalase in the incubation medium. These results support the view that oxidative stress during ischemia-reperfusion may contribute towards the occurrence of intracellular Ca2+ overload and subsequent cell damage by depressing the sarcolemmal mechanisms governing the efflux of Ca2+ from the cardiac cell. 相似文献