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KB Cullberg T Christiansen SK Paulsen JM Bruun SB Pedersen B Richelsen 《Obesity (Silver Spring, Md.)》2013,21(3):454-460
Background:
Vascular growth is a prerequisite for adipose tissue (AT) development and expansion. Some AT cytokines and hormones have effects on vascular development, like vascular endothelial growth factor (VEGF‐A), angiopoietin (ANG‐1), ANG‐2 and angiopoietin‐like protein‐4 (ANGPTL‐4).Methods:
In this study, the independent and combined effects of diet‐induced weight loss and exercise on AT gene expression and proteins levels of those angiogenic factors were investigated. Seventy‐nine obese males and females were randomized to: 1. Exercise‐only (EXO; 12‐weeks exercise without diet‐restriction), 2. Hypocaloric diet (DIO; 8‐weeks very low energy diet (VLED) + 4‐weeks weight maintenance diet) and 3. Hypocaloric diet and exercise (DEX; 8‐weeks VLED + 4‐weeks weight maintenance diet combined with exercise throughout the 12 weeks). Blood samples and fat biopsies were taken before and after the intervention.Results:
Weight loss was 3.5 kg in the EXO group and 12.3 kg in the DIO and DEX groups. VEGF‐A protein was non‐significantly reduced in the weight loss groups. ANG‐1 protein levels were significantly reduced 22‐25% after all three interventions (P < 0.01). The ANG‐1/ANG‐2 ratio was also decreased in all three groups (P < 0.05) by 27‐38%. ANGPTL‐4 was increased in the EXO group (15%, P < 0.05) and 9% (P < 0.05) in the DIO group. VEGF‐A, ANG‐1, and ANGPTL‐4 were all expressed in human AT, but only ANGPTL‐4 was influenced by the interventions.Conclusions:
Our data show that serum VEGF‐A, ANG‐1, ANG‐2, and ANGPTL‐4 levels are influenced by weight changes, indicating the involvement of these factors in the obese state. Moreover, it was found that weight loss generally was associated with a reduced angiogenic activity in the circulation. 相似文献3.
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KB Gudmundsdóttir S Sigurdarson J Kristinsson T Eiríksson T Jóhannesson 《Acta veterinaria Scandinavica》2006,48(1):16-5
This study was undertaken in order to examine whether any connection existed between the amounts of iron in forage and the
sporadic occurrence of scrapie observed in certain parts of Iceland. As iron and manganese are considered antagonistic in
plants, calculation of the Fe/Mn ratios was also included by using results from Mn determination earlier performed in the
same samples. Forage samples (n = 170) from the summer harvests of 2001–2003, were collected from 47 farms for iron and manganese
analysis. The farms were divided into four categories: 1. Scrapie-free farms in scrapie-free areas (n = 9); 2. Scrapie-free farms in scrapie-afflicted areas (n = 17); 3. Scrapie-prone farms (earlier scrapie-afflicted, restocked farms) (n = 12); 4. Scrapie-afflicted farms (n = 9). Farms in categories 1 and 2 are collectively referred to as scrapie-free farms. The mean iron concentration in forage samples from scrapie-afflicted farms was significantly higher than in forage samples
from farms in the other scrapie categories (P = 0.001). The mean Fe/Mn ratio in forage from scrapie-afflicted farms was significantly
higher than in forage from scrapie-free and scrapie-prone farms (P < 0.001). The results indicated relative dominance of iron
over manganese in forage from scrapie-afflicted farms as compared to farms in the other categories. Thus thorough knowledge
of iron, along with manganese, in soil and vegetation on sheep farms could be a pivot in studies on sporadic scrapie. 相似文献
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Scanning electron microscopy and gramicidin patch clamp recordings of microvillous receptor neurons dissociated from the rat vomeronasal organ 总被引:2,自引:1,他引:1
Vomeronasal organs from female rats were dissociated and isolated
microvillous receptor neurons were studied. The isolated receptor neurons
kept the typical bipolar shape which they have in situ as observed by
scanning electron microscopy. We applied the perforated patch-clamp
technique using the cation-selective ionophore gramicidin on freshly
isolated and well differentiated receptor neurons. The mean resting
potential was -58+/-14 mV (n=39). The contribution of the sodium pump
current to the resting potential was demonstrated by lowering the K+
concentration in the bath or by application of 100 microM dihydro-ouabain.
The input resistance was in the range of 1-6 GOmega and depolarizing
current pulses of a few pA were sufficient to trigger overshooting action
potentials. In voltage clamp conditions a fast transient sodium inward
current and a sustained outward potassium current were activated by
membrane depolarization. These observations indicate that freshly isolated
vomeronasal receptor neurons of rats can be recorded, using gramicidin,
with little modification of the intracellular content. Their
electrophysiological properties are very similar to those observed in situ.
Four out of eight female vomeronasal receptor cells were depolarized by
diluted rat male urine.
相似文献
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The comet assay is now the method of choice for measuring most kinds of DNA damage in cells. However, due to the lack of a standardised protocol inter-laboratory comparisons are of limited value. The aim of this paper is to demonstrate how small changes in comet-assay variables may significantly affect the results. We examined the effect of varying agarose concentrations, alkaline unwinding time, electrophoresis time, voltage and current, by use of two cell types, viz. human peripheral blood lymphocytes and the lymphoblastoid cell line TK-6. All these variables have marked effects on assay performance and, therefore, on the determination of DNA damage. Here we identify factors of particular importance. 相似文献
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cAMP-mediated inhibition of DNA replication and S phase progression: involvement of Rb, p21Cip1, and PCNA 总被引:4,自引:0,他引:4 下载免费PDF全文
cAMP exerts an antiproliferative effect on a number of cell types including lymphocytes. This effect of cAMP is proposed to be mediated by its ability to inhibit G1/S transition. In this report, we provide evidence for a new mechanism whereby cAMP might inhibit cellular proliferation. We show that elevation of intracellular levels of cAMP inhibits DNA replication and arrests the cells in S phase. The cAMP-induced inhibition of DNA synthesis was associated with the increased binding of p21Cip1 to Cdk2-cyclin complexes, inhibition of Cdk2 kinase activity, dephosphorylation of Rb, and dissociation of PCNA from chromatin in S phase cells. The ability of cAMP to inhibit DNA replication and trigger release of PCNA from chromatin required Rb and p21Cip1 proteins, since both processes were only marginally affected by increased levels of cAMP in Rb-/- and p21Cip1-/- 3T3 fibroblasts. Importantly, the implications of cAMP-induced inhibition of DNA synthesis in cancer treatment was demonstrated by the ability of cAMP to reduce apoptosis induced by S phase-specific cytotoxic drugs. Taken together, these results demonstrate a novel role for cAMP in regulation of DNA synthesis and support a model in which activation of cAMP-dependent signaling protects cells from the effect of S phase-specific antitumor agents. 相似文献
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Gutzkow KB Låhne HU Naderi S Torgersen KM Skålhegg B Koketsu M Uehara Y Blomhoff HK 《Cellular signalling》2003,15(9):871-881
The purpose of the present study was to understand the mechanism by which activated protein kinase A (PKA) leads to down-regulation of cyclin D3 in lymphocytes. By using Jurkat cells as a model system, we have been able to demonstrate that cyclin D3 is reduced at the level of translation by inhibition of elongation. One of the important factors involved in translational elongation is the eukaryotic elongation factor 2 (eEF2). eEF2 promotes translation in its unphosphorylated form, and we observed a rapid phosphorylation of the eEF2-protein upon forskolin treatment. When using specific inhibitors of the eEF2-kinase prior to forskolin treatment, we were able to inhibit the increased phosphorylation of eEF2. Furthermore, inhibition of eEF2-kinase prevented the forskolin-mediated down-regulation of cyclin D3. Taken together, it appears that activation of PKA in Jurkat cells reduces the expression of cyclin D3 at the level of translational elongation by increasing the phosphorylation of eEF2 and thereby inhibiting its activity. 相似文献
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Patrick Royston Friederike M-S Barthel Mahesh KB Parmar Babak Choodari-Oskooei Valerie Isham 《Trials》2011,12(1):1-18