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31.
Pérez-Vizcaíno F López-López JG Santiago R Cogolludo A Zaragozá-Arnáez F Moreno L Alonso MJ Salaices M Tamargo J 《American journal of physiology. Lung cellular and molecular physiology》2002,283(4):L839-L848
The maturation in the vasodilator response to nitric oxide (NO) in isolated intrapulmonary arteries was analyzed in newborns and 15- to 20-day-old piglets. The vasodilator responses to NO gas but not to the NO donor sodium nitroprusside increased with age. The inhibitory effects of the superoxide dismutase inhibitor diethyldithiocarbamate and xanthine oxidase plus hypoxanthine and the potentiation induced by superoxide dismutase and MnCl(2) of NO-induced vasodilatation were similar in the two age groups. Diphenyleneiodonium (NADPH oxidase inhibitor) potentiated the response to NO, and this effect was more pronounced in the older animals. The nonselective cyclooxygenase inhibitors indomethacin and meclofenamate and the preferential cyclooxygenase-1 inhibitor aspirin augmented NO-induced relaxation specifically in newborns, whereas the selective cycloxygenase-2 inhibitor NS-398 had no effect. The expressions of alpha-actin, cycloxygenase-1, and cycloxygenase-2 proteins were similar, whereas Cu,Zn-superoxide dismutase decreased with age. Therefore, the present data suggest that the maturational increase in the vasodilatation of NO in the pulmonary arteries during the first days of extrauterine life involves a cycloxygenase-dependent inhibition of neonatal NO activity. 相似文献
32.
Engineering increased vitamin C levels in plants by overexpression of a D-galacturonic acid reductase 总被引:18,自引:0,他引:18
Agius F González-Lamothe R Caballero JL Muñoz-Blanco J Botella MA Valpuesta V 《Nature biotechnology》2003,21(2):177-181
L-Ascorbic acid (vitamin C) in fruits and vegetables is an essential component of human nutrition. Surprisingly, only limited information is available about the pathway(s) leading to its biosynthesis in plants. Here, we report the isolation and characterization of GalUR, a gene from strawberry that encodes an NADPH-dependent D-galacturonate reductase. We provide evidence that the biosynthesis of L-ascorbic acid in strawberry fruit occurs through D-galacturonic acid, a principal component of cell wall pectins. Expression of GalUR correlated with changing ascorbic acid content in strawberry fruit during ripening and with variations in ascorbic acid content in fruit of different species of the genus Fragaria. Reduced pectin solubilization in cell walls of transgenic strawberry fruit with decreased expression of an endogenous pectate lyase gene resulted in lower ascorbic acid content. Overexpression of GalUR in Arabidopsis thaliana enhanced vitamin C content two- to threefold, demonstrating the feasibility of engineering increased vitamin C levels in plants using this gene. 相似文献
33.
Transcriptome analysis of root transporters reveals participation of multiple gene families in the response to cation stress 总被引:31,自引:4,他引:27
34.
Altered Na+ and Li+ Homeostasis in Saccharomyces cerevisiae Cells Expressing the Bacterial Cation Antiporter NhaA 下载免费PDF全文
Roc Ros Consuelo Montesinos Abraham Rimon Etana Padan Ramn Serrano 《Journal of bacteriology》1998,180(12):3131-3136
The bacterial Na+(Li+)/H+ antiporter NhaA has been expressed in the yeast Saccharomyces cerevisiae. NhaA was present in both the plasma membrane and internal membranes, and it conferred lithium but not sodium tolerance. In cells containing the yeast Ena1-4 (Na+, Li+) extrusion ATPase, the extra lithium tolerance conferred by NhaA was dependent on a functional vacuolar H+ ATPase and correlated with an increase of lithium in an intracellular pool which exhibited slow efflux of cations. In yeast mutants without (Na+, Li+) ATPase, lithium tolerance conferred by NhaA was not dependent on a functional vacuolar H+ ATPase and correlated with a decrease of intracellular lithium. NhaA was able to confer sodium tolerance and to decrease intracellular sodium accumulation in a double mutant devoid of both plasma membrane (Na+, Li+) ATPase and vacuolar H+ ATPase. These results indicate that the bacterial antiporter NhaA expressed in yeast is functional at both the plasma membrane and the vacuolar membrane. The phenotypes conferred by its expression depend on the functionality of plasma membrane (Na+, Li+) ATPase and vacuolar H+ ATPase. 相似文献
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Luz-María Torres Liliana Rivera-Espinosa Juan L. Chávez-Pacheco Carlos F. Navas Joel A. Demetrio Radamés Alemón-Medina Francisca Trujillo Martín Pérez Martha M. Zapata Rocío Cárdenas Citlaltepetl Salinas Arnoldo Aquino Rafael Velázquez-Cruz Manuel-de-Jesús Castillejos 《PloS one》2015,10(11)
Ifosfamide blood concentrations are necessary to monitor its therapeutic response, avoiding any adverse effect. We developed and validated an analytical method by UPLC-MS/MS to quantify ifosfamide in dried blood spots (DBS). Blood samples were collected on Whatman 903® filter paper cards. Five 3 mm disks were punched out from each dried blood spot. Acetonitrile and ethyl acetate were used for drug extraction. Chromatographic separation was carried out in an Acquity UPLC equipment with a BEH-C18 column, 2.1 x 100 mm, 1.7 μm (Waters®). The mobile phase consisted in 5 mM ammonium formate and methanol:acetonitrile (40:48:12 v/v/v) at 0.2 mL/min. LC-MS/MS detection was done by ESI+ and multiple reaction mode monitoring, ionic transitions were m/z1+ 260.99 > 91.63 for ifosfamide and 261.00 > 139.90 for cyclophosphamide (internal standard). This method was linear within a 100–10000 ng/mL range and it was accurate, precise and selective. Ifosfamide samples in DBS were stable for up to 52 days at -80°C. The procedure was tested in 14 patients, ages 1 month to 17 years (9 males and 5 females), with embryonic tumours treated with ifosfamide, alone or combined, at a public tertiary referral hospital. Ifosfamide blood levels ranged from 11.1 to 39.7 μmol/L at 12 hours after the last infusion, while 24-hour levels ranged from 0.7–19.7 μmol/L. The median at 12 hours was 19.5 μmol/L (Q25 14.4–Q75 29.0) and 3.8 μmol/L (Q25 1.5–Q75 9.9) at 24 hours, p<0.001. This method is feasible to determine ifosfamide plasma levels in paediatric patients. 相似文献
38.
Jesús Mu?oz-Bertomeu Borja Cascales-Mi?ana Manuel Alaiz Juan Segura Roc Ros 《Plant signaling & behavior》2010,5(1):67-69
Glycolysis is a central metabolic pathway that provides energy and generates precursors for the synthesis of primary metabolites such as amino acids and fatty acids.1–3 In plants, glycolysis occurs in the cytosol and plastids, which complicates the understanding of this essential process.1 As a result, the contribution of each glycolytic pathway to the specific primary metabolite production and the degree of integration of both pathways is still unresolved. The glycolytic glyceraldehyde-3-phosphate dehydrogenase (GAPDH) catalyzes the conversion of glyceraldehyde-3-phosphate to 1,3-bisphosphoglycerate. Both cytosolic (GAPCs) and plastidial (GAPCps) GAPDH activities have been described biochemically. But, up to now, little attention had been paid to GAPCps, probably because they have been considered as “minor isoforms” that catalyze a reversible reaction in plastids where it has been assumed that key glycolytic intermediates are in equilibrium with the cytosol. In the associated study,4 we have elucidated the crucial role of Arabidopsis GAPCps in the control of primary metabolism in plants. GAPCps deficiency affects amino acid and sugar metabolism and impairs plant development. Specifically, GAPCp deficiency affects the serine supply to roots, provoking a drastic phenotype of arrested root development. Also, we show that the phosphorylated serine biosynthesis pathway is critical to supply serine to non-photosynthetic organs such as roots. These studies provide new insights of the contribution of plastidial glycolysis to plant metabolism and evidence the complex interactions existing between metabolism and development.Key words: GAPDH, glycolysis, serine biosynthesis, Arabidopsis, plastid 相似文献
39.
Rocío Torreblanca Sergio Cerezo Elena Palomo-Ríos José A. Mercado Fernando Pliego-Alfaro 《Plant Cell, Tissue and Organ Culture》2010,103(1):61-69
Olive tree, Olea europaea L., is one of the most commercially important oil crops. A reliable protocol for the genetic transformation of this species
has been developed. Embryogenic calli were infected with different Agrobacterium tumefaciens strains harboring pBINUbiGUSint or pGUSINT binary plasmids. These vectors contain the nos-nptII and the uidA gene driven by the maize polyubiquitin Ubi1 and CaMV35S promoter, respectively. Inoculated explants were cocultured for 2 days, and later selected in the presence of 200 mg l−1 paromomycin. The inclusion of a 3 weeks selection period in liquid medium supplemented with 50 mg l−1 paromomycin was critical for elimination of chimaeric calli. Agrobacterium strain AGL1 containing pBINUbiGUSint plasmid yielded higher transformation frequencies than EHA105 or LBA4404. Globular somatic
embryos (SE), 1–2 mm diameter, cultured in the selection medium in groups of three, were the best explant for transformation.
Using this protocol, transformation frequencies in the range of 20–45%, based on the number of infected explants proliferating
in the selection medium, have been obtained. More than 100 independent transgenic lines were generated, and 16 of them converted
to plants. Transgenic plants were acclimated and grown in the greenhouse, being phenotypically similar to wild type plants.
The uidA gene was strongly expressed in transgenic material during the in vitro regeneration phase; however, β-glucuronidase (GUS)
activity in pBINUbiGUSint transgenic plants was neither detected in shoots growing in vitro nor in acclimated plants. Transgenic
leaves, however, contained high levels of NPTII protein. By contrast, plants transformed with the pGUSINT plasmid showed a
strong GUS activity in leaves. The protocol here described will allow the genetic improvement of this traditional crop. 相似文献
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