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排序方式: 共有552条查询结果,搜索用时 31 毫秒
1.
Christiane Gulat-Marnay rée Lafitte Jean-Michel Arrang Jean-Charles Schwartz 《Journal of neurochemistry》1990,55(1):47-53
The opioid modulation of histamine release was studied in rat brain slices labeled with L-[3H]histidine. The K(+)-induced [3H]histamine release from cortical slices was progressively inhibited by the preferential kappa-agonists ketocyclazocine, dynorphin A (1-13), Cambridge 20, spiradoline, U50,488H, and U69,593 in increasing concentrations. In contrast, the mu-agonists morphine, morphiceptin, and Tyr-D-Ala-Gly-(NMe)Phe-Gly-ol (DAGO) were ineffective as were the preferential delta-agonists [D-Ala2,D-Leu5]enkephalin (DA-DLE) and [D-Pen2,D-Pen5]enkephalin (DPDPE). Nor-binaltorphimine (nor-BNI) and MR 2266, two preferential kappa-antagonists, reversed the inhibitory effect of the various kappa-agonists more potently than did naloxone, with mean Ki values of 4 nM and 25 nM, respectively. The effects of ketocyclazocine and naloxone also were seen in slices of rat striatum, another brain region known to contain histaminergic nerve endings. We conclude that kappa-opioid receptors, presumably located on histaminergic axons, control histamine release in the brain. However, nor-BNI and naloxone failed, when added alone, to enhance significantly [3H]histamine release from cerebral cortex or striatum, and bestatin, an aminopeptidase inhibitor, failed to decrease K(+)-evoked [3H]histamine release. These two findings suggest that under basal conditions these kappa-opioid receptors are not tonically activated by endogenous dynorphin peptides. The inhibition of cerebral histamine release by kappa-agonists may mediate the sedative actions of these agents in vivo. 相似文献
2.
Christiane Gulat-Marnay rée Lafitte Jean-Michel Arrang Jean-Charles Schwartz 《Journal of neurochemistry》1989,52(1):248-254
The cholinergic modulation of histamine release and synthesis was studied in rat brain slices or synaptosomes labeled with L-[3H]histidine. Carbachol in increasing concentrations progressively reduced the K+-induced [3H]histamine release from cortical slices. Pirenzepine, a preferential M1-receptor antagonist, reversed the carbachol effect in an apparently competitive manner and with Ki values of 1-6 X 10(-8) M. 11-[(2-[(Diethylamino)methyl]-1-piperidinyl)acetyl]-5,11-dihydro-6H- pyrido[2,3-b][1,4]benzodiazepine-6-one (AF-DX 116), considered a preferential M2-receptor antagonist, reversed the carbachol effect with a mean Ki of approximately 2 X 10(-7) M. Oxotremorine behaved as a partial agonist in the modulation of histamine release. Neostigmine, an acetylcholinesterase inhibitor, inhibited the K+-induced release of [3H]histamine from cortical slices, and the effect was largely reversed by pirenzepine, an observation suggesting a modulation by endogenous acetylcholine. The effects of carbachol and pirenzepine were observed with slices of other brain regions known to contain histaminergic nerve terminals or perikarya, as well as with cortical synaptosomes. The two drugs also modified, in opposite directions, [3H]histamine formation in depolarized cortical slices. In vivo oxotremorine inhibited [3H]histamine formation in cerebral cortex, and this effect was reversed by scopolamine. When administered alone, scopolamine failed to enhance significantly the 3H- labeled amine formation, a finding suggesting that muscarinic receptors are not activated by endogenous acetylcholine released under basal conditions. It is concluded that muscarinic heteroreceptors, directly located on histaminergic nerve terminals, control release and synthesis of histamine in the brain. These receptors apparently belong to the broad M1-receptor category and may correspond to a receptor subclass displaying a rather high affinity for AF-DX 116. 相似文献
3.
Linkage analysis of schizophrenia with five dopamine receptor genes in nine pedigrees 总被引:2,自引:0,他引:2
Hilary Coon William Byerley John Holik Mark Hoff Marina Myles-Worsley Lars Lannfelt Pierre Sokoloff Jean-Charles Schwartz Merilyne Waldo Robert Freedman Rosemarie Plaetke 《American journal of human genetics》1993,52(2):327-334
Alterations in dopamine neurotransmission have been strongly implicated in the pathogenesis of schizophrenia for nearly 2 decades. Recently, the genes for five dopamine receptors have been cloned and characterized, and genetic and physical map information has become available. Using these five loci as candidate genes, we have tested for genetic linkage to schizophrenia in nine multigenerational families which include multiple affected individuals. In addition to testing conservative disease models, we have used a neurophysiological indicator variable, the P50 auditory evoked response. Deficits in gating of the P50 response have been shown to segregate with schizophrenia in this sample and may identify carriers of gene(s) predisposing for schizophrenia. Linkage results were consistently negative, indicating that a defect at any of the actual receptor sites is unlikely to be a major contributor to schizophrenia in the nine families studied. 相似文献
4.
Wing Y. Cheung Jean-Charles Côté Diane L. Benoit Benoit S. Landry 《Plant Molecular Biology Reporter》1993,11(2):142-155
We have designed a simple and rapid assay for chloroplast-based triazine resistance in higher plants using PCR amplification
of thepsbA gene coupled toMaeI digestion of the amplified product to distinguish triazine resistant from sensitive biotypes. Our assay is universal and
avoids the need of lengthy procedures of previously published assays, which either required spraying of seedlings in a controlled
environment, quantification of chlorophyll fluorescence of leaf discs after incubation in triazine solution, DNA sequencing
of thepsbA gene, or Southern-blot analysis. Our diagnostic system is qualitative, reliable, fast and simple. More than 100 seedlings
taken directly from the field can be analyzed in one day. This system has a direct application towards a more rational use
of herbicides in production fields. It also represents a valuable tool to monitor spreading of resistant biotypes through
time and space and can serve as a model system applicable to other gene monitoring needs. 相似文献
5.
Sébastien Derégnaucourt & Jean-Charles Guyomarc'h 《Ethology : formerly Zeitschrift fur Tierpsychologie》2003,109(2):107-119
Each year, thousands of domestic Japanese and hybrid quails are released within the breeding range of the European quail. We showed recently that no post‐zygotic isolating mechanisms have yet been established between these subspecies. The aim of this study was to investigate whether pre‐zygotic mechanisms are strong enough to prevent hybridization. We tested the level of subspecies selectivity in females of European and Japanese quail respectively using playbacks of European, hybrid and Japanese male mating calls. European quail females emitted the greatest number of rally calls in response to mating calls by conspecific males. Their responses were the weakest to mating calls produced by males of the other subspecies and intermediate to mating calls by hybrid males. In contrast, Japanese quails produced similar responses to all types of mating calls. These results suggest that mixed pairs could form in the wild. The European quail could thus become one of the most endangered galliforms of the Western Palearctic. 相似文献
6.
Abstract: Substrate utilization of microbial cells extracted from soil with a 0.85% aqueous sodium chloride solution, was determined to estimate effects on soil microorganisms at the community level with microtiter plates (Biolog GN®) containing 95 different sources of organic carbon. A consistent pattern of utilized substrates was obtained after 24 h of microtiter plate incubation at 28°C. The absorbance values (OD590 ) obtained from a microtiter plate reader after background correction were transformed by using the average absorbance values of oxidized substrates as a threshold to distinguish between well utilized and poorly or non-utilized substrates and thereby reduce variances between replicates. Doubling times of the extracted soil microorganisms in the microtiter plates were tested with 12 substrates and ranged from 1.96 h to 3.23 h, depending on the carbon source. The carbon source utilization assay was used to assess the effects of soil inoculation with Corynebacterium glutamicum with and without a genetically engineered plasmid (pUN1; 6.3 kb), which encoded for the synthesis of the mammalian protease inhibiting peptide, aprotinin. Additionally, aprotinin itself was added at two concentrations to soil samples. An identical decrease in the number of carbon sources utilized, especially carbohydrates, occurred upon soil inoculation with both C. glutamicum strains after inoculation with 106 cells g−1 soil. This effect was only detectable during the first three weeks of incubation, as long as cell numbers of C. glutamicum (pUN1) were above 105 cfu g−1 . Soil amendment with aprotinin resulted in utilization of additional substrates, most of them carbohydrates. With 0.1 mg aprotinin g−1 soil this stimulation lasted 2 days and with 10 mg g−1 it lasted for 7 days. 相似文献
7.
Nathalie Griffon Catherine Pilon François Sautel Jean-Charles Schwartz Pierre Sokoloff 《Journal of neurochemistry》1997,68(1):1-9
Abstract: As cerebral neurons express the dopamine D1 receptor positively coupled with adenylyl cyclase, together with the D3 receptor, we have investigated in a heterologous cell expression system the relationships of cyclic AMP with D3 receptor signaling pathways. In NG108-15 cells transfected with the human D3 receptor cDNA, dopamine, quinpirole, and other dopamine receptor agonists inhibited cyclic AMP accumulation induced by forskolin. Quinpirole also increased mitogenesis, assessed by measuring [3 H]thymidine incorporation. This effect was blocked partially by genistein, a tyrosine kinase inhibitor. Forskolin enhanced by 50–75% the quinpirole-induced [3 H]thymidine incorporation. This effect was maximal with 100 n M forskolin, occurred after 6–16 h, was reproduced by cyclic AMP-permeable analogues, and was blocked by a protein kinase A inhibitor. Forskolin increased D3 receptor expression up to 135%, but only after 16 h and at concentrations of >1 µ M . Thus, in this cell line, the D3 receptor uses two distinct signaling pathways: it efficiently inhibits adenylyl cyclase and induces mitogenesis, an effect possibly involving tyrosine phosphorylation. Activation of the cyclic AMP cascade potentiates the D3 receptor-mediated mitogenic response, through phosphorylation by a cyclic AMP-dependent kinase of a yet unidentified component. Hence, transduction of the D3 receptor can involve both opposite and synergistic interactions with cyclic AMP. 相似文献
8.
Several lines of evidence indicate that the i.v. injection of 3H-pimozide results in a specific in vivo binding of the neuroleptic to dopaminergic receptors.First, 3H-pimozide is preferentially accumulated in the striatum as compared to non-dopaminergic structures like the cerebellum. Second, the selective accumulation of 3H-pimozide is prevented by prior administration of various neuroleptics as well as by apomorphine. Moreover, doses of antagonists which prevent this accumulation were identical to those which lead to an increased striatal HVA level. Third, 3H-pimozide accumulation is not modified by the administration of a variety of non-dopaminergic agents.However, 3H-pimozide binding is not prevented either by indirect dopamine agonists and is even greatly increased by d-amphetamine at high doses. The possibility that direct or indirect dopamine agonists may favour the binding of the antagonist through a modification of receptor sites is discussed. 相似文献
9.
Durgeau A El Hage F Vergnon I Validire P de Montpréville V Besse B Soria JC van Hall T Mami-Chouaib F 《Journal of immunology (Baltimore, Md. : 1950)》2011,187(11):5532-5539
Decreased antigenicity of cancer cells is a major problem in tumor immunology. This is often acquired by an expression defect in the TAP. However, it has been reported that certain murine Ags appear on the target cell surface upon impairment of TAP expression. In this study, we identified a human CTL epitope belonging to this Ag category. This epitope is derived from preprocalcitonin (ppCT) signal peptide and is generated within the endoplasmic reticulum by signal peptidase and signal peptide peptidase. Lung cancer cells bearing this antigenic peptide displayed low levels of TAP, but restoration of their expression by IFN-γ treatment or TAP1 and TAP2 gene transfer abrogated ppCT Ag presentation. In contrast, TAP upregulation in the same tumor cells increased their recognition by proteasome/TAP-dependent peptide-specific CTLs. Thus, to our knowledge, ppCT(16-25) is the first human tumor epitope whose surface expression requires loss or downregulation of TAP. Lung tumors frequently display low levels of TAP molecules and might thus be ignored by the immune system. Our results suggest that emerging signal peptidase-generated peptides represent alternative T cell targets, which permit CTLs to destroy TAP-impaired tumors and thus overcome tumor escape from CD8(+) T cell immunity. 相似文献
10.
Bienvenut WV Déon C Pasquarello C Campbell JM Sanchez JC Vestal ML Hochstrasser DF 《Proteomics》2002,2(7):868-876
Although peptide mass fingerprinting is currently the method of choice to identify proteins, the number of proteins available in databases is increasing constantly, and hence, the advantage of having sequence data on a selected peptide, in order to increase the effectiveness of database searching, is more crucial. Until recently, the ability to identify proteins based on the peptide sequence was essentially limited to the use of electrospray ionization tandem mass spectrometry (MS) methods. The recent development of new instruments with matrix-assisted laser desorption/ionization (MALDI) sources and true tandem mass spectrometry (MS/MS) capabilities creates the capacity to obtain high quality tandem mass spectra of peptides. In this work, using the new high resolution tandem time of flight MALDI-(TOF/TOF) mass spectrometer from Applied Biosystems, examples of successful identification and characterization of bovine heart proteins (SWISS-PROT entries: P02192, Q9XSC6, P13620) separated by two-dimensional electrophoresis and blotted onto polyvinylidene difluoride membrane are described. Tryptic protein digests were analyzed by MALDI-TOF to identify peptide masses afterward used for MS/MS. Subsequent high energy MALDI-TOF/TOF collision-induced dissociation spectra were recorded on selected ions. All data, both MS and MS/MS, were recorded on the same instrument. Tandem mass spectra were submitted to database searching using MS-Tag or were manually de novo sequenced. An interesting modification of a tryptophan residue, a "double oxidation", came to light during these analyses. 相似文献