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101.
Patte-Mensah C Kappes V Freund-Mercier MJ Tsutsui K Mensah-Nyagan AG 《Journal of neurochemistry》2003,86(5):1233-1246
Neurosteroids are steroids produced within the nervous system. Based on behavioural responses evoked in animals by synthetic steroid injections, several studies suggested neurosteroid involvement in important neurophysiological processes. These observations should be correlated only to neuroactive effects of the injected steroids. Neurosteroids mostly control the CNS activity through allosteric modulation of neurotransmitter receptors within concentration ranges used by neurotransmitters themselves. Therefore, neurosteroid production within pathways controlling a neurophysiological process is necessary to consider neurosteroid involvement in that process. Because of the increasing speculation about pain modulation by neurosteroids based on pharmacological observations, we decided to clarify the situation by investigating neurosteroidogenesis occurrence in sensory pathways, particularly in nociceptive structures. We studied the presence and activity of cytochrome P450side chain cleavage (P450scc) in rat pain pathways. P450scc-immunoreactive cells were localized in dorsal root ganglia (DRG), spinal cord (SC) dorsal horn, nociceptive supraspinal nuclei (SSN) and somatosensory cortex. Incubation of DRG, SSN or SC tissue homogenates with [3H]cholesterol yielded the formation of radioactive metabolites including [3H]pregnenolone of which the synthesis was reduced in presence of aminogluthetimide, a P450scc inhibitor. These first neuroanatomical and neurochemical results demonstrate the occurrence of neurosteroidogenesis in nociceptive pathways and strongly suggest that neurosteroids may control pain mechanisms. 相似文献
102.
103.
Kurar E Barendse W Bottema CD Davis S Föster M Kalm E Kappes SM Kister A Lewin HA Klungland H Medjugorac I Olsaker I Pitchford WS Schmutz SM Taylor J Thomsen H Kirkpatrick BW 《Animal genetics》2002,33(6):460-463
This study describes development of a consensus genetic linkage map of bovine chromosome 24 (BTA24). Eight participating laboratories contributed data for 58 unique markers including a total of 25 409 meioses. Eighteen markers, which were typed in more than one reference population, were used as potential anchors to generate a consensus framework map. The framework map contained 16 loci ordered with odds greater than 1000:1 and spanned 79.3 cM. Remaining markers were included in a comprehensive map relative to these anchors. The resulting BTA24 comprehensive map was 98.3 cM in length. Average marker intervals were 6.1 and 2.5 cM for framework and comprehensive maps, respectively. Marker order was generally consistent with previously reported BTA24 linkage maps. Only one discrepancy was found when comparing the comprehensive map with the published USDA-MARC linkage map. Integration of genetic information from different maps provides a high-resolution BTA24 linkage map. 相似文献
104.
Van Dam EW Roelfsema F Veldhuis JD Helmerhorst FM Frölich M Meinders AE Krans HM Pijl H 《American journal of physiology. Endocrinology and metabolism》2002,282(4):E865-E872
We hypothesized that short-term calorie restriction would blunt luteinizing hormone (LH) hypersecretion in obese women with polycystic ovary syndrome (PCOS) and thereby ameliorate the anovulatory endocrine milieu. To test this hypothesis, 15 obese patients with PCOS and nine age- and body mass index-matched healthy women underwent 24-h blood sampling to quantitate plasma LH, leptin, and insulin levels. PCOS subjects were prescribed a very low caloric liquid diet (4.2 MJ/day) for 7 days and were then resampled. Basal and pulsatile LH secretion was threefold higher in PCOS subjects, but plasma insulin and leptin levels were not different in the calorie-replete state. Contrary to expectation, calorie restriction enhanced basal and pulsatile LH secretion even further. As expected, plasma glucose, insulin, and leptin concentrations decreased by 18, 75, and 50%, respectively. Serum total testosterone concentration fell by 23%, whereas serum estrone, estradiol, sex hormone-binding globulin (SHBG), and androstenedione concentrations remained unchanged. Enhanced LH secretion in the presence of normal metabolic and hormonal adaptations to calorie restriction points to anomalous feedback control of pituitary LH release in PCOS. 相似文献
105.
Part of Ran is associated with AKAP450 at the centrosome: involvement in microtubule-organizing activity 总被引:9,自引:0,他引:9 下载免费PDF全文
Keryer G Di Fiore B Celati C Lechtreck KF Mogensen M Delouvee A Lavia P Bornens M Tassin AM 《Molecular biology of the cell》2003,14(10):4260-4271
The small Ran GTPase, a key regulator of nucleocytoplasmic transport, is also involved in microtubule assembly and nuclear membrane formation. Herein, we show by immunofluorescence, immunoelectron microscopy, and biochemical analysis that a fraction of Ran is tightly associated with the centrosome throughout the cell cycle. Ran interaction with the centrosome is mediated by the centrosomal matrix A kinase anchoring protein (AKAP450). Accordingly, when AKAP450 is delocalized from the centrosome, Ran is also delocalized, and as a consequence, microtubule regrowth or anchoring is altered, despite the persisting association of gamma-tubulin with the centrosome. Moreover, Ran is recruited to Xenopus sperm centrosome during its activation for microtubule nucleation. We also demonstrate that centrosomal proteins such as centrin and pericentrin, but not gamma-tubulin, AKAP450, or ninein, undertake a nucleocytoplasmic exchange as they concentrate in the nucleus upon export inhibition by leptomycin B. Together, these results suggest a challenging possibility, namely, that centrosome activity could depend upon nucleocytoplasmic exchange of centrosomal proteins and local Ran-dependent concentration at the centrosome. 相似文献
106.
Overeem S Kok SW Lammers GJ Vein AA Frölich M Meinders AE Roelfsema F Pijl H 《American journal of physiology. Endocrinology and metabolism》2003,284(3):E641-E647
Narcolepsy is a sleep disorder caused by impaired hypocretin (orexin) neurotransmission. Growth hormone (GH) secretion may be altered in narcolepsy for various reasons. Slow-wave sleep episodes, which are closely associated with GH-secretory events, are more randomly dispersed over 24 h in narcoleptics. Furthermore, hypocretins may inhibit pituitary GH release. We assessed the function of the somatotropic axis in narcolepsy by deconvolving 24-h (10-min sampling interval) plasma GH concentration profiles in seven hypocretin-deficient narcoleptic patients and in seven healthy controls matched for age, sex, and body weight. Both basal and pulsatile GH secretion rate and secretagogue-induced GH release were similar in patients and controls. However, narcoleptics secreted approximately 50% of their total production during the daytime, whereas controls secreted only 25% during the day. Also, the GH output pattern of narcoleptics was significantly less regular. We propose that hypocretin deficiency disrupts the circadian distribution of hypothalamic GH-releasing hormone release in narcoleptic patients to simultaneously cause daytime GH release and promote their propensity to fall asleep during the day. 相似文献
107.
A second-generation linkage map of the sheep genome 总被引:32,自引:0,他引:32
Maurico J. de Gortari Brad A. Freking Rachel P. Cuthbertson Steven M. Kappes John W. Keele Roger T. Stone Kreg A. Leymaster Ken G. Dodds Allan M. Crawford Craig W. Beattie 《Mammalian genome》1998,9(3):204-209
A genetic map of Ovis aries (haploid n = 27) was developed with 519 markers (504 microsatellites) spanning ∼3063 cM in 26 autosomal linkage groups and
127 cM (female specific) of the X Chromosome (Chr). Genotypic data were merged from the IMF flock (Crawford et al., Genetics
140, 703, 1995) and the USDA mapping flock. Seventy-three percent (370/504) of the microsatellite markers on the map are common
to the USDA-ARS MARC cattle linkage map, with 27 of the common markers derived from sheep. The number of common markers per
homologous linkage group ranges from 5 to 22 and spans a total of 2866 cM (sex average) in sheep and 2817 cM in cattle. Marker
order within a linkage group was consistent between the two species with limited exceptions. The reported translocation between
the telomeric end of bovine Chr 9 (BTA 9) and BTA 14 to form ovine Chr 9 is represented by a 15-cM region containing 5 common
markers. The significant genomic conservation of marker order will allow use of linkage maps in both species to facilitate
the search for quantitative trait loci (QTLs) in cattle and sheep.
Received: 20 September 1992 / Accepted: 18 November 1997 相似文献
108.
Fuchs Marc Klas Ferdinand E. McFerson James R. Gonsalves Dennis 《Transgenic research》1998,7(6):449-462
Transgenic melon and squash containing the coat protein (CP) gene of the aphid transmissible strain WL of cucumber mosaic cucumovirus (CMV) were grown under field conditions to determine if they would assist the spread of the aphid non-transmissible strain C of CMV, possibly through heterologous encapsidation and recombination. Transgenic melon were susceptible to CMV strain C whereas transgenic squash were resistant although the latter occasionally developed chlorotic blotches on lower leaves. Transgenic squash line ZW-20, one of the parents of commercialized cultivar Freedom II, which expresses the CP genes of the aphid transmissible strains FL of zucchini yellow mosaic (ZYMV) and watermelon mosaic virus 2 (WMV 2) potyviruses was also tested. Line ZW-20 is resistant to ZYMV and WMV 2 but is susceptible to CMV. Field experiments conducted over two consecutive years showed that aphid-vectored spread of CMV strain C did not occur from any of the CMV strain C-challenge inoculated transgenic plants to any of the uninoculated CMV-susceptible non- transgenic plants. Although CMV was detected in 3% (22/764) of the uninoculated plants, several assays including ELISA, RT- PCR-RFLP, identification of CP amino acid at position 168, and aphid transmission tests demonstrated that these CMV isolates were distinct from strain C. Instead, they were non-targeted CMV isolates that came from outside the field plots. This is the first report on field experiments designed to determine the potential of transgenic plants expressing CP genes for triggering changes in virus-vector specificity. Our results indicate that transgenic plants expressing CP genes of aphid transmissible strains of CMV, ZYMV, and WMV 2 are unlikely to mediate the spread of aphid non-transmissible strains of CMV. This finding is of practical relevance because transgenic crops expressing the three CP genes are targeted for commercial release, and because CMV is economically important, has a wide host range, and is widespread worldwide. 相似文献
109.
Ricarda Jahnel Olaf Bender Lisa M Münter Mathias Dreger Clemens Gillen Ferdinand Hucho 《European journal of biochemistry》2003,270(21):4264-4271
The vanilloid-like TRP-channel VRL-1 (TRPV2) is a nonselective cation channel expressed by primary sensory neurons and non-neuronal tissues [Caterina, M.J., Rosen, T.A., Tominaga, M., Brake, A.J and Julius, D. (1999) Nature 398, 436-441]. It is one of the six members of the vanilloid-like TRP-channel family which is now termed the TRPV family [Montell, G., Birnbaumer, L., Flockerzi, V., Bindels, R.J., Brutford, E.A., Caterina, M.J., Clapham, D.E., Harteneck, C., Heller, S., Julius, D., Kojima, I., Mori, Y., Penner, R., Prawitt, D., Scharenberg, A.M., Schultz, G., Shimizu, N. and Zhu, M.X. (2002) Mol. Cell 2, 229-231]. As it is a temperature-gated channel, VRL-1 appears to be functionally related to VR1. In contrast to VR1, VRL-1 is activated at a higher temperature threshold and it does not respond to capsaicin or protons. Here we describe the expression of VRL-1 in the rat dorsal root ganglion-derived cell line F-11, a hybridoma of mouse neuroblastoma (N18TG2) and rat dorsal root ganglion cells. We found by RT-PCR that F-11 cells express not only the rat VRL-1, but also its mouse orthologue in a single cell. The F-11 parental cell line N18TG2 also expressed murine VRL-1. Due to its neuronal character, the DRG-derived F-11 cell line provides an experimental system for the study of VRL-1 biochemistry. However, one has to be aware that both the mouse and the rat protein are expressed simultaneously. Furthermore we cloned VRL-1 from rat brain and analyzed its glycosylation and localization in comparison to the endogenously expressed protein in F-11 cells. In contrast to the endogenous VRL-1 the overexpressed protein is glycosylated. Similar to VR1 the glycosylation is N-linked as shown by an deglycosylation assay. Immunofluorescence analysis of the endogenous VRL-1 in F-11 cells gives only weak signals in the cytoplasm whereas the overexpressed rat VRL-1 appears mainly at the plasma membrane. 相似文献
110.
Gabriela B. Gomez Nicola Foster Daniella Brals Heleen E. Nelissen Oladimeji A. Bolarinwa Marleen E. Hendriks Alexander C. Boers Diederik van Eck Nicole Rosendaal Peju Adenusi Kayode Agbede Tanimola M. Akande Michael Boele van Hensbroek Ferdinand W. Wit Catherine A. Hankins Constance Schultsz 《PloS one》2015,10(9)