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51.
Shi H Noguchi N Xu Y Niki E 《Biochemical and biophysical research communications》1999,257(3):651-656
Peroxynitrite resulted from the reaction of nitric oxide and superoxide anion has been implicated in the genesis of neurotoxicity. In this study, the oxidation of phospholipids in rat brain synaptosomes induced by peroxynitrite generated from 3-morpholinosydnonimine (SIN-1) was studied in vitro. The formation and accumulation of phospholipid hydroperoxides, including phosphatidylcholine hydroperoxide (PCOOH) and phosphatidyl-ethanolamine hydroperoxide (PEOOH) in rat brain synaptosomes induced by peroxynitrite, were observed. PEOOH and PCOOH were formed rapidly and SIN-1 concentration-dependently. The hydroperoxides formed in synaptosomes were unstable and it was suggested that phospholipase A2 played a role in degradation of the hydroperoxides. The endogenous alpha-tocopherol acted as a potent antioxidant. It was oxidized very rapidly and concentration-dependently by SIN-1 to alpha-tocopheryl quinone. Furthermore, uric acid was found to be an effective antioxidant in inhibiting oxidative damage to synaptosomal lipids induced by SIN-1. The results provide direct evidence to show that peroxynitrite can not only deplete alpha-tocopherol, but also cause production of phospholipid hydroperoxides resulting in disrupted brain tissue. 相似文献
52.
Saito Y Shiga A Yoshida Y Furuhashi T Fujita Y Niki E 《Bioscience, biotechnology, and biochemistry》2004,68(4):781-786
Rosemary is commonly used as a spice and a flavoring agent in food processing. Although the antioxidative properties of its extracts have been investigated, there have been few reports on the volatile components of rosemary. We designed a novel antioxidative system which can generate the volatile constituents in the gaseous phase from a rosemary extract and evaluated the gaseous antioxidative activities against both lipid peroxidation and cell death induced by nitrogen dioxide and ultraviolet radiation. The antioxidative effects of the major volatile components on the oxidation of linoleic acid induced by azo compounds were also investigated in a solution. The volatile components in the novel antioxidative system suppressed the Jurkat cell death induced by nitrogen dioxide and the intracellular formation of reactive oxygen species in fibroblast cells induced by ultraviolet radiation. 1,8-Cineole among the volatile components exerted an antioxidative effect against the oxidation of linoleic acid in a solution induced by azo compounds and ultraviolet radiation. These data suggest that the volatile constituents of a rosemary extract had antioxidative properties and that gaseous exposure antioxidant is a promising method for promoting health. 相似文献
53.
Detection of lipid peroxidation in vivo: total hydroxyoctadecadienoic acid and 7-hydroxycholesterol as oxidative stress marker 总被引:3,自引:0,他引:3
It is important to assess the oxidative injury in vivo accurately and inclusively, as the oxidative stress induced by various oxidants in a random and destructive fashion is considered to play an important role in the pathophysiology of a number of human disorders and diseases. We have developed an improved method for the measurement of lipid peroxidation in vivo, where total hydroxyoctadecadienoic acids (HODE) and 7-hydroxycholesterol (FCOH) were determined by GC/MS analysis from physiological samples after reduction with sodium borohydride and saponification by potassium hydroxide. In this method, both free and ester forms of hydroperoxides and ketones as well as hydroxides of linoleate and cholesterol are measured as HODE and FCOH, respectively. The ratio of stereo-isomers, (E,E)-HODE/(E,Z)-HODE, could be also measured. The plasma concentrations of total HODE were obtained as 76.5, 666 and 2225 nM for human, rat and mouse, respectively. It was found that HODE and FCOH could be measured satisfactorily by the present method from plasma, erythrocyte and urine of humans and experimental animals. It was also found that HODE in urine arose from both free and ester forms, while 8-iso-prostaglandin F2alpha was present primarily as a free acid form. As the concentrations of HODE were much higher than 8-iso-prostaglandin F2alpha, HODE may well be used as a good oxidative marker in vivo. 相似文献
54.
Comparative study on the action of tocopherols and tocotrienols as antioxidant: chemical and physical effects 总被引:5,自引:0,他引:5
alpha-Tocopherol is known as the most abundant and active form of vitamin E homologues in vivo, but recently the role of other forms of vitamin E has received renewed attention. The antioxidant properties were compared for alpha-, beta-, gamma- and delta-tocopherols and tocotrienols. The following results were obtained: (1). the corresponding tocopherols and tocotrienols exerted the same reactivities toward radicals and the same antioxidant activities against lipid peroxidation in solution and liposomal membranes; (2). tocopherols gave more significant physical effect than tocotrienols on the increase in rigidity at the membrane interior; (3). tocopherols and tocotrienols showed similar mobilities within the membranes, but tocotrienols were more readily transferred between the membranes and incorporated into the membranes than tocopherols; (4). alpha-tocopherol and alpha-tocotrienol, but not the other forms, reduced Cu(II) to give Cu(I) together with alpha-tocopheryl and alpha-tocotrienyl quinones, respectively and exerted prooxidant effect in the oxidation of methyl linoleate in SDS micelles. 相似文献
55.
Uchida M Shimatsu Y Onoe K Matsuyama N Niki R Ikeda JE Imai H 《Transgenic research》2001,10(6):577-582
Miniature pig is an attractive animal for a wide range of research fields, such as medicine and pharmacology, because of its small size, the possibility of breeding it under minimum environmental controls and the physiology that is potentially similar to that of human. Although transgenic technology is useful for the analysis of gene function and for the development of model animals for various diseases, there have not yet been any reports on producing transgenic miniature pig. This study is the first successful report concerning the production of transgenic miniature pig by pronuclear microinjection. The huntingtin gene cloned from miniature pig, which is a homologue of candidate gene for Huntington's disease, connected with rat neuron-specific enolase promoter region, was injected into a pronucleus of fertilized eggs with micromanipulator. The eggs were transferred into the oviduct of recipient miniature pigs, whose estrus cycles were previously synchronized with a progesterone analogue. A total of 402 injected eggs from 171 donors were transferred to 23 synchronized recipients. Sixteen of them maintained pregnancy and delivered 65 young, and one resulted in abortion. Five of the 68 offspring (three of which were aborted) were determined to have transgene by PCR and Southern analysis. The overall rate of transgenic production was 1.24% (transgenic/injected eggs). This study provides the first success and useful information regarding production of transgenic miniature pig for biomedical research. 相似文献
56.
We studied the sleep-wake behavior of mentally retarded people from late winter to early summer at 60 degrees N. During this time the daylength increased 8 h 51 min. The data were collected by observing the sleep-wake status of 293 subjects at 20-min intervals for five randomized 24h periods (= recording days). The intervals during which the individual recording days of the same order (1st, 2nd, etc.) were carried out, were called recording periods. Consequently, there were five recording periods, each containing 293 individual recording days. Even though there was overlap among the recording periods, the median daylength from one period to another increased approximately by 100 min. In the initial statistical analysis, the number of wake-sleep transitions was found to differ significantly among the five recording periods (Friedman test, p < 0.001). The mean ranks in the Friedman test suggested that the number of wake-sleep transitions was highest during the 1st and lowest during the 5th recording period. In further statistical analyses using a program for mixed effects regression analysis (MIXOR 2.0) it was found that the increase in daylength during the study period was associated with a simultaneous decrease of approximately 0.5 wake-sleep transitions in the whole study population (p < 0.001). The decrease in the number of wake-sleep transitions was significant only in the subgroups of subjects with a daylength change of more than 350 min between the 1st and 5th recording days (Wilcoxon tests, p < 0.005). This suggests that after a marked prolongation of the natural photoperiod, the reduction in sleep episodes was more probable than after smaller changes in daylength. It is concluded that the sleep of mentally retarded people living in a rehabilitation center at a northern latitude is more fragmented in winter than in early summer and that the change is related probably to the simultaneous increase in the length of the natural photoperiod. The sleep quality of persons living in institutional settings might be improved by increasing the intensity and/or duration of daily artificial light exposure during the darker seasons. 相似文献
57.
Scaplehorn N Holmström A Moreau V Frischknecht F Reckmann I Way M 《Current biology : CB》2002,12(9):740-745
The Wiskott-Aldrich syndrome protein family member N-WASP is a key integrator of the multiple signalling pathways that regulate actin polymerization via the Arp2/3 complex. Our previous studies have shown that N-WASP is required for the actin-based motility of vaccinia virus and is recruited via Nck and WIP. We now show that Grb2 is an additional component of the vaccinia actin tail-forming complex. Recruitment of Nck and Grb2 to viral particles requires phosphorylation of tyrosine residues 112 and 132 of A36R, the vaccinia actin tail nucleator, respectively. The presence of Grb2 on the virus is also dependent on the polyproline-rich region of N-WASP. The Grb2 pathway alone is therefore unable to nucleate actin tails, as its recruitment requires the prior recruitment of N-WASP by Nck. However, Grb2 does play an important role in actin-based motility of vaccinia, as in its absence, the mean number of actin tails per cell is reduced 2.6-fold. Thus, both Nck and Grb2 act in a cooperative manner to stabilize and/or activate the vaccinia actin-nucleating complex. We suggest that such cooperativity between "primary" and "secondary" adaptor proteins is likely to be a general feature of receptor-mediated signalling. 相似文献
58.
Receptor-mediated monitoring of tissue well-being via detection of soluble heparan sulfate by Toll-like receptor 4 总被引:32,自引:0,他引:32
Johnson GB Brunn GJ Kodaira Y Platt JL 《Journal of immunology (Baltimore, Md. : 1950)》2002,168(10):5233-5239
Perturbations to the well-being of tissues in plants and invertebrates generate fragments of endogenous molecules that are recognized by innate immune receptors. Vertebrates have homologous receptors on specialized cells such as dendritic cells, but whether these receptors respond to fragments of endogenous molecules is not known. We tested the idea that Toll-like receptors on dendritic cells might recognize polysaccharide fragments of heparan sulfate proteoglycan. Dendritic cells were found to mature in response to heparan sulfate as measured by costimulatory protein expression, morphology, and T lymphocyte stimulation, but this maturation was absent when Toll-like receptor 4 was mutated or inhibited. These findings suggest that Toll-like receptors in vertebrates may monitor tissue well-being by recognizing fragments of endogenous macromolecules. 相似文献
59.
In Silene vulgaris (M.) G. cell culture three growth phases were distinguished, namely, a lag phase, an exponential phase and a stationary phase. Pectin termed silenan and an acidic arabinogalactan were isolated as cell wall polysaccharides of S. vulgaris callus at the different growth phases during culture. Production of silenan as the galacturonan (or rhamnogalacturonan) core was observed at the beginning of the exponential phase and at the stationary phase of the callus growth. Arabinogalactan, containing the galacturonic acid residues, is formed at the exponential phase followed by attachment to the core of silenan in the middle of the exponential phase. The arabinogalactan constituent of silenan appeared to be destroyed gradually at the stationary growth phase. The monosaccharide compositions of silenan and arabinogalactan were determined at various phases of the callus growth. Silenan was found to be formed in maximum amounts at the exponential phase of the cell growth. Insignificant alterations of the yields of acidic arabinogalactan were found during culture while total productivity per litre of medium and rate of production per day of arabinogalactan were found to be maximal at the exponential phase of growth. 相似文献
60.
A comparison of the plant growth retardant activity of the chlamydocin analogues, compound 1, six derivatives from 1 and 2, and two synthetic analogues revealed that there are two types of retardant in chlamydocin analogues. One, for example in compound 1, requires an oxygen atom at C-8 of the 2-aminodecanoic acid moiety to show retardant activity. The other, for example in compound 8, requires no oxygen atom at C-8 but requires a specific alkyl group chain length for activity. To determine the differences in mode of action of both types of retardant, rice seedlings were separately treated with compounds 1 and 8, and after appearance of dwarfism, their endogenous ABA and GA(1) levels were determined and compared to those of the control. Treatment with 1 (10 nmol/plant) increased ABA levels 4 times higher than that of the control and decreased GA(1) levels to 20% of that of the control. Treatment with 8 (30 nmol/plant) did not affect the ABA level but decreased GA(1) content to 5% of that of the control. 相似文献