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41.
Acutely administered melatonin reduces oxidative damage in lung and brain induced by hyperbaric oxygen 总被引:3,自引:0,他引:3
Pablos Marta I.; Reiter Russel J.; Chuang Jin-Ing; Ortiz Genaro G.; Guerrero Juan M.; Sewerynek Ewa; Agapito Maria T.; Melchiorri Daniela; Lawrence Richard; Deneke Susan M. 《Journal of applied physiology》1997,83(2):354-358
Pablos, Marta I., Russel J. Reiter, Jin-Ing Chuang, GenaroG. Ortiz, Juan M. Guerrero, Ewa Sewerynek, Maria T. Agapito, DanielaMelchiorri, Richard Lawrence, and Susan M. Deneke. Acutely administered melatonin reduces oxidative damage in lung and brain induced by hyperbaric oxygen. J. Appl.Physiol. 83(2): 354-358, 1997.Hyperbaric oxygenexposure rapidly induces lipid peroxidation and cellular damage in avariety of organs. In this study, we demonstrate that the exposure ofrats to 4 atmospheres of 100% oxygen for 90 min is associated withincreased levels of lipid peroxidation products [malonaldehyde(MDA) and 4-hydroxyalkenals (4-HDA)] and withchanges in the activities of two antioxidative enzymes[glutathione peroxidase (GPX) and glutathione reductase (GR)], as well as in the glutathione status in the lungs and in the brain. Products of lipid peroxidation increased after hyperbaric hyperoxia, both GPX and GR activities were decreased, and levels oftotal glutathione (reduced+oxidized) and glutathione disulfide (oxidized glutathione) increased in both lung and brain areas (cerebralcortex, hippocampus, hypothalamus, striatum, and cerebellum) but not inliver. When animals were injected with melatonin (10 mg/kg) immediatelybefore the 90-min hyperbaric oxygen exposure, all measurements ofoxidative damage were prevented and were similar to those in untreatedcontrol animals. Melatonin's actions may be related to a variety ofmechanisms, some of which remain to be identified, including itsability to directly scavenge free radicals and its induction ofantioxidative enzymes via specific melatonin receptors. 相似文献
42.
We have studied the presence of a cloned fragment of DNA from Drosophila melanogaster in other organisms by means of nucleic acid hybridization analysis. The isolated region is localized in polytene chromosomes at the 63F subdivision. This region includes a puff that responds within minutes to ecdysone stimulation. We have found that 63F DNA from D. melanogaster hybridizes 'in situ' to both DNA and RNA from D. simulans, D. teissieri, and D. hydei. In all these species the isolated DNA remains associated with one early-ecdysone stimulated puff. The isolated Drosophila recombinant DNA is also complementary to polyadenylated RNA from foetal and adult rat liver but fails to hybridize to the nonpolyadenylated RNA classes from both sources and to polyadenylated RNA from rat mammary glands. 相似文献
43.
Marta Elisa Vázquez-Memije Alfonso Cárabez-Trejo Graciela Gallardo-Trillanes Graciela Delhumeau-Ongay 《Archives of biochemistry and biophysics》1984,232(2):441-449
Rat testis mitochondrial ATPase was not inhibited by oligomycin at pH 7.5. It was inhibited only at higher alkaline pH's, and showed a lower sensitivity both to oligomycin and N,N′-dicyclohexylcarbodiimide and a higher one to efrapeptin. In submitochondrial particles, testis ATPase was only slightly inhibited by oligomycin, ossamycin, and efrapeptin. The possibility of a loose binding of F1 to the membrane was supported by its recovery from the supernatant of the submitochondrial particles. Furthermore, by electron microscopy, after hypoosmotic shock and negative staining of the mitochondrial preparations, most of the inner mitochondrial membranes showed only a few “knobs” or none at all. The capacity of the testis mitochondrial preparation to produce ATP was tested and compared to that from liver. ATP synthetase/ATPase activity ratio was in liver mitochondria, whereas in the testis it was . In spite of this large difference, at least part of the testis ATPase must be firmly bound to the membrane, since it is able to form ATP. The rest seems to be loosely bound and its functional significance is still unknown. 相似文献
44.
In extracts obtained by treating rye embryo ribosomes with 0.5 M NH4Cl, nuclease activity was noted towards double-stranded RNA from virus of Penicillium chrysogenum and towards synthetic poly (A)-poly (U) and poly (I)-poly (C) complexes. 相似文献
45.
I. Marta Evans Ronald R. D. Croy Philippa Hutchinson Donald Boulter Peter I. Payne Margaret E. Gordon 《Planta》1979,144(5):455-462
Polyribosomes which have template activity in the wheat germ system have been isolated from developing pea seeds. Some of the translation products have identical mobilities to the vicilin and legumin subunits by SDS-PAGE. Certain products were specifically immunoprecipitated with antisera prepared against purified vicilin and legumin fractions. Various RNA fractions including poly A-rich RNA have also been isolated from polyribosomes and shown to direct the synthesis of polyripeptides whose properties are similar to the storage protein subunits. The results are discussed in relationship to other investigations with seed storage protein biosynthesis in vitro.Abbreviations DTT
dithiothreitol
- SDS-PAGE
SDS-polyacrylamide gel electrophoresis
- TCA
tricarboxylic acid 相似文献
46.
Extrachromosomal DNA in Thiobacillus A2 总被引:1,自引:0,他引:1
47.
The pollination biology and breeding system of Vellozia squamata (Velloziaceae), a species of cerrado vegetation in Central Brazil, were studied. V. squamata is unusual in being pollinated by a few, generalist bee species despite having very large flowers, and having a distinctive pulsed flowering phenology. The species is self-incompatible but with a late-acting, post-fertilization rejection mechanism. 相似文献
48.
Manuel Rico Jorge Santoro Carlos González Marta Bruix José Luis Neira José Luis Nieto José Herranz 《Journal of biomolecular NMR》1991,1(3):283-298
Summary A method is proposed to generate initial structures in cases where the distance geometry method may fail, such as when the set of1H NMR NOE-based distance constraints is small in relation to the size of the protein. The method introduces an initial correlation between the and backbone angles (based on empirical observations) which is relaxed in later stages of the calculation. The obtained initial structures are refined by well-established methods of energy minimization and restrained molecular dynamics. The method is applied to determine the solution structure of Ribonuclease A (124 residues) from a NOE basis consisting of 467 NOE cross-correlations (97 intra-residue, 206 sequential, 23 medium-range and 141 long-range) obtained at 360 MHz. The global shape and backbone overall fold of the eight final refined structures are close to those shown by the crystal structure. A meaningful difference in the positioning of the catalytically important His119 side chain in the solution and crystal structures has been detected. 相似文献
49.
50.
NAD-linked lactate, malate, glycerophosphate, alcohol and nonspecific dehydrogenases, aspartate aminotransferases, and soluble esterases from extracts of tissues of individuals from a wild population of Calomys musculinus (Rodentia, Cricetidae) have been analyzed by means of starch gel electrophoresis and specific staining. Allelic frequencies and heterozygosity have been determined. Mendelian inheritance of some of the variants detected was confirmed by breeding experiments. Ten out of fifteen (66.6%) of the genetic loci investigated presented polymorphism. Mean heterozygosity per locus was very high (H=0.2014, se 0.046).This work has been supported, in part, by grants from the Secretaria de Ciencia y Tecnología de la Nación (National Program for Endemic Diseases) and from the Fundación Emilio Ocampo. C. N. G. is a Fellow and A. B. a Career Investigator of the Consejo Nacional de Investigaciones Científicas y Técnicas of Argentina. 相似文献