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排序方式: 共有626条查询结果,搜索用时 15 毫秒
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Increased efflux rather than oxidation is the mechanism of glutathione depletion by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) 总被引:2,自引:0,他引:2
D Di Monte M S Sandy M T Smith 《Biochemical and biophysical research communications》1987,148(1):153-160
Incubation of isolated hepatocytes in the presence of either the parkinsonian-inducing compound 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or its putative toxic metabolite 1-methyl-4-phenylpyridinium ion (MPP+) led to a depletion of intracellular reduced glutathione (GSH), which was mostly recovered as glutathione disulfide (GSSG). However, both MPTP- and MPP+-induced glutathione perturbances were relatively unaffected by the prior inhibition of glutathione reductase with 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU), suggesting that intracellular oxidation was not the major mechanism involved in the GSH loss. Inclusion of cystine in the incubation mixtures revealed a time-dependent formation of cysteinyl glutathione (CySSG), indicating that an increased efflux was mostly responsible for the MPTP- and MPP+-induced GSH depletion. Therefore, the measurement of GSSG, which is apparently formed extracellularly, was not associated with oxidative stress. 相似文献
4.
Goats and some sheep synthesize a juvenile hemoglobin, Hb C (alpha 2 beta
C2), at birth and produce this hemoglobin exclusively during severe anemia.
Sheep that synthesize this juvenile hemoglobin are of the A haplotype.
Other sheep, belonging to a separate group, the B haplotype, do not
synthesize hemoglobin C and during anemia continue to produce their adult
hemoglobin. To understand the basis for this difference we have determined
the structural organization of the beta- globin locus of B-type sheep by
constructing and isolating overlapping genomic clones. These clones have
allowed us to establish the linkage map 5' epsilon I-epsilon II-psi beta
I-beta B-epsilon III-epsilon IV- psi beta II-beta F3' in this haplotype.
Thus, B sheep lack four genes, including the BC gene, and have only eight
genes, compared with the 12 found in the goat globin locus. The goat
beta-globin locus is as follows: 5' epsilon I-epsilon II-psi beta X-beta
C-epsilon III-epsilon IV-psi beta Z-beta A-epsilon V-epsilon VI-psi beta
Y-beta F3'. Southern blot analysis of A-type sheep reveals that these
animals have a beta- globin locus similar to that of goat, i.e., 12 globin
genes. Thus, the beta-globin locus of B-haplotype sheep resembles that of
cows and may have retained the duplicated locus of the ancestor of cows and
sheep. Alternatively, the B-sheep locus arrangement may be the result of a
deletion of a four-gene set from the triplicated locus.
相似文献
5.
Sarah A. Jewell Donato Di Monte Plinio Richelmi Giorgio Bellomo Sten Orrenius 《Journal of biochemical and molecular toxicology》1986,1(3):13-22
Incubation of isolated rat hepatocytes with tert-butylhydroperoxide resulted in marked cytotoxicity preceded by intracellular glutathione depletion and extensive lipid peroxidation. Addition of antioxidants delayed, but did not prevent, this toxicity. A significant decrease in protein-free sulfhydryl groups also, occurred in the presence of tert-butylhydroperoxide; direct oxidation of protein thiols and mixed disulfide formation with glutathione were responsible for this decrease. The involvement of protein thiol depletion in tert-butylhydroperoxide–induced cytotoxicity is suggested by our observation that administration of dithiothreitol, which caused re-reduction of the oxidized sulfhydryl groups and mixed disulfides, efficiently protected the cells from toxicity. Moreover, depletion of intracellular glutathione by pretreatment of the hepatocytes with diethyl maleate accelerated and enhanced the depletion of protein thiols induced by tert-butylhydroperoxide and potentiated cell toxicity even in the absence of lipid peroxidation. 相似文献
6.
Unequal synthesis of globin chains after extended incubation of rabbit reticulocytes with L-O-methylthreonine 总被引:1,自引:0,他引:1
Rabbit reticulocytes were incubated in vitro as long as 20 hr with l-O-methyl threonine, the OMT was removed, and the capacity of the cells to synthesize α- and β-globin chains was determined. After 20 hr incubation in vitro, OMT-treated cells can make β chains about twice as well as cells incubated for 20 hr without OMT. However, the capacity of OMT-treated cells to synthesize α chains was only about 60% that of cells incubated without OMT for 20 hr. These results suggest that the capacity of reticulocytes to produce a specific globin chain after an in vitro incubation correlates positively with the number of ribosomes associated with the specific messenger RNA for that chain during the incubation. 相似文献
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Patrick T. Curry Terry Ziemer Gerhard Van der Horst Warren Burgess Monte Straley Robert W. Atherton Robert M. Kitchin 《Molecular reproduction and development》1989,22(1):27-36
Ejaculated sperm from the domestic ferret (Mustela putorius furo) and the black-footed ferret (Mustela nigripes) were compared for differences in morphological abnormalities and argentophilic protein distribution. Thawed domestic ferret sperm was also compared to fresh sperm to determine whether there were any effects on cell morphology due to cryopreservation. There were statistically significant differences between the two species of ferret in two of the categories scored. The domestic ferret had a higher frequency of cells that were bent in the midpiece and in the principal piece, and a higher frequency of headless and tailless cells when compared to the black-footed ferret. There were no statistically significant differences in cell morphology between the fresh and cryopreserved ejaculates of the domestic ferret employing a standard egg yolk cryoextender. Silver nitrate staining distribution was different between the two species in both the head and tail region. 相似文献