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991.
This study examined sensory nerves associated with mesenteric arteries and veins in sham and deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Reactivity of arteries and veins to substances released from sensory nerves was also studied in vitro using computer-assisted video microscopy. Co-localization of substance P (SP) and calcitonin gene-related peptide (CGRP) immunoreactivity (ir) was used to evaluate perivascular sensory nerves. Radioimmunoassay was used to quantify SP- and CGRP-ir content. Immunohistochemical studies revealed a plexus of SP/CGRP-ir nerves associated with arteries and veins. The intensity of SP-ir, but not CGRP-ir labeling was greater in arteries and veins from DOCA-salt compared to sham rats. RIA measurements revealed that the CGRP-ir content of arteries and veins was higher than the SP-ir content but there was a significant increase in SP-ir, but not CGRP-ir, content in arteries and veins from DOCA-salt rats. SP (0.03-1 microM) contracted veins and the NK-3 receptor agonist, senktide, mimicked this effect. There were no differences in SP or senktide reactivity of veins from sham or DOCA-salt rats. SP, but not senktide, relaxed KCl (40 mM) preconstricted arteries. CGRP (0.3 microM), acetylcholine (10 microM) and capsaicin (1 microM) relaxed KCl-preconstricted arteries and veins. The NK-1 receptor agonist, substance P methyl ester relaxed arteries but not veins. These data indicate that DOCA-salt hypertension is associated with upregulation of SP content in perivascular nerves. NK-3 receptors mediate venoconstriction which is unchanged in DOCA-salt hypertension. Increased release of SP from perivenous nerves might contribute to the increased venomotor tone in DOCA-salt hypertension. 相似文献
992.
The present study used voltammetry to ascertain whether electrically stimulated somatodendritic dopamine release in ventral tegmental area slices from C57BL/6 and dopamine transporter knockout mice was due to exocytosis or dopamine transporter reversal, as has been debated. The maximal concentration of electrically evoked dopamine release was similar between ventral tegmental area slices from dopamine transporter knockout and C57BL/6 mice. Dopamine transporter blockade (10 μM nomifensine) in slices from C57BL/6 mice inhibited dopamine uptake but did not alter peak evoked dopamine release. In addition, dopamine release and uptake kinetics in ventral tegmental area slices from dopamine transporter knockout mice were unaltered by the norepinephrine transporter inhibitor, desipramine (10 μM), or the serotonin transporter inhibitor, fluoxetine (10 μM). Furthermore, maximal dopamine release in ventral tegmental area slices from both C57BL/6 and dopamine transporter knockout mice was significantly decreased in response to Na+ channel blockade by 1 μM tetrototoxin, removal of Ca2+ from the perfusion media and neuronal vesicular monoamine transporter inhibition by RO-04-1284 (10 μM) or tetrabenazine (10 and 100 μM). Finally, the glutamate receptor antagonists AP-5 (50 and 100 μM) and CNQX (20 and 50 μM) had no effect on peak somatodendritic dopamine release in C57BL/6 mice. Overall, these data suggest that similar mechanisms, consistent with exocytosis, govern electrically evoked dopamine release in ventral tegmental area slices from C57BL/6 and dopamine transporter knockout mice. 相似文献
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994.
The transcriptional histone acetyltransferase cofactor TRRAP associates with the MRN repair complex and plays a role in DNA double-strand break repair 下载免费PDF全文
Robert F Hardy S Nagy Z Baldeyron C Murr R Déry U Masson JY Papadopoulo D Herceg Z Tora L 《Molecular and cellular biology》2006,26(2):402-412
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Metabolic profiles and genetic diversity of denitrifying communities in activated sludge after addition of methanol or ethanol 总被引:1,自引:0,他引:1
External carbon sources can enhance denitrification rates and thus improve nitrogen removal in wastewater treatment plants. The effects of adding methanol and ethanol on the genetic and metabolic diversity of denitrifying communities in activated sludge were compared using a pilot-scale plant with two parallel lines. A full-scale plant receiving the same municipal wastewater, but without external carbon source addition, was the reference. Metabolic profiles obtained from potential denitrification rates with 10 electron donors showed that the denitrifying communities altered their preferences for certain compounds after supplementation with methanol or ethanol and that methanol had the greater impact. Clone libraries of nirK and nirS genes, encoding the two different nitrite reductases in denitrifiers, revealed that methanol also increased the diversity of denitrifiers of the nirS type, which indicates that denitrifiers favored by methanol were on the rise in the community. This suggests that there might be a niche differentiation between nirS and nirK genotypes during activated sludge processes. The composition of nirS genotypes also varied greatly among all samples, whereas the nirK communities were more stable. The latter was confirmed by denaturing gradient gel electrophoresis of nirK communities on all sampling occasions. Our results support earlier hypotheses that the compositions of denitrifier communities change during predenitrification processes when external carbon sources are added, although no severe effect could be observed from an operational point of view. 相似文献
998.
Elli M Callegari ML Ferrari S Bessi E Cattivelli D Soldi S Morelli L Goupil Feuillerat N Antoine JM 《Applied and environmental microbiology》2006,72(7):5113-5117
Whether Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus can be recovered after passage through the human gut was tested by feeding 20 healthy volunteers commercial yogurt. Yogurt bacteria were found in human feces, suggesting that they can survive transit in the gastrointestinal tract. 相似文献
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Oved S Mosesson Y Zwang Y Santonico E Shtiegman K Marmor MD Kochupurakkal BS Katz M Lavi S Cesareni G Yarden Y 《The Journal of biological chemistry》2006,281(31):21640-21651
When appended to the epidermal growth factor receptor (EGFR), ubiquitin serves as a sorting signal for lysosomal degradation. Here we demonstrate that the ubiquitin ligase of EGFR, namely c-Cbl, also mediates receptor modification with the ubiquitin-like molecule Nedd8. EGF stimulates receptor neddylation, which enhances subsequent ubiquitylation, as well as sorting of EGFR for degradation. Multiple lysine residues, located within the tyrosine kinase domain of EGFR, serve as attachment sites for Nedd8. A set of clathrin coat-associated binders of ubiquitin also bind Nedd8, but they undergo ubiquitylation, not neddylation. We discuss the emerging versatility of the concerted action of ubiquitylation and neddylation in the process that desensitizes growth factor-activated receptor tyrosine kinases. 相似文献