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排序方式: 共有858条查询结果,搜索用时 15 毫秒
1.
目的探讨牛磺酸(NHS)对老年大鼠骨量流失的影响,并探讨可能的机制。方法将30只大鼠随机分为对照组(CON)、模型组(MOD)以及牛磺酸组(NHS),每组10只;其中NHS组大鼠每天接受牛磺酸(2 g/kg)治疗12周;待治疗结束后通过Micro-CT检测、HE染色切片、血清指标、蛋白质印迹观察治疗效果,探讨可能的机制。结果治疗12周后,与MOD组相比,三点弯曲试验、Micro-CT和HE染色切片结果显示NHS组大鼠的骨小梁数量、骨强度和骨密度(bone mineral density,BMD)得到明显改善。NHS组大鼠最大载荷和弹性模量、BMD、TV/BV、Tb.N、Tb.Th和Tb.Sp较OVX组明显改善(P<0.05)。和MOD组比较,NHS治疗后大鼠血清BLAP、P1NP、TRACP-5b和β-CTX水平明显降低,组间差异有统计学意义(P<0.05)。和MOD组比较,NHS组Runx2、BMP2、Beclin-1和LC3Ⅱ/LC3-Ⅰ表达水平明显上调,而P62表达水平显著下调,比较差异有统计学意义(P<0.05)。结论NHS可能通过激活自噬,从而对年龄引起的骨量丢失起到保护作用。 相似文献
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The changes in endogenous amino acids in brain extracellular and intracellular compartments evoked by hyposmotic stress and energy deprivation were compared. Tissue content and release of ten amino acids were measured simultaneously in rat hippocampal slices by means of high performance liquid chromatography Hyposmotic stress induced a large release of taurine (25568 pmol mg-7 protein), and a smaller release of glutamate, accompanied by an inverse change in tissue content. Adding mannitol to correct osmolarity blocked these changes. Energy deprivation caused an increase in the release of all amino acids except glutamine. The release was particularly large for glutamate and GABA (31141 and 13282 pmol mg–1 respectively). The intracellular concentrations were generally reduced, but the total amount of the released amino acids increased. In contrast to the effect seen during hyposmolar stress, mannitol enhanced the changes due to energy deprivation. The results show that hyposmolar stress and energy deprivation cause different content and release profiles, suggesting that the mechanisms involved in the two situations are either different, or modulated in different ways. The intracellular amino acid depletion seen during energy deprivation shows that increased outward transport is probably a primary eventL, and increased amino acid formation likely secondary to this release. [Neurol Res 1995; 17: 402–408] 相似文献
3.
Stefan Branth Leif Hambraeus Karin Piehl-Aulin Birgitta Essén-Gustavsson Torbjörn Åkerfeldt Roger Olsson 《Upsala journal of medical sciences》2013,118(1):12-25
Few studies have examined energy metabolism during prolonged, strenuous exercise. We wanted therefore to investigate energy metabolic consequences of a prolonged period of continuous strenuous work with very high energy expenditure. Twelve endurance-trained athletes (6 males and 6 females) were recruited. They performed a 7-h bike race on high work-load intensity. Physiological, biochemical, endocrinological, and anthropometric muscular compartment variables were monitored before, during, and after the race. The energy expenditure was high, being 5557 kcal. Work-load intensity (% of VO2 peak) was higher in females (77.7%) than in men (69.9%). Muscular glycogen utilization was pronounced, especially in type I fibres (>90%). Additionally, muscular triglyceride lipolysis was considerably accelerated. Plasma glucose levels were increased concomitantly with an unchanged serum insulin concentration which might reflect an insulin resistance state in addition to proteolytic glyconeogenesis. Increased reactive oxygen species (malondialdehyde (MDA)) were additional signs of metabolic stress. MDA levels correlated with glycogen utilization rate. A relative deficiency of energy substrate on a cellular level was indicated by increased intracellular water of the leg muscle concomitantly with increased extracellular levels of the osmoregulatory amino acid taurine. A kindred nature of a presumed insulin-resistant state with less intracellular availability of glucose for erythrocytes was also indicated by the findings of decreased MCV together with increased MCHC (haemoconcentration) after the race. This strenuous energy-demanding work created a metabolic stress-like condition including signs of insulin resistance and deteriorated intracellular glucose availability leading to compromised fuelling of ion pumps, culminating in a disturbed cellular osmoregulation indicated by taurine efflux and cellular swelling. 相似文献
4.
《Toxicology mechanisms and methods》2013,23(4):305-308
Sodium fluoride (NaF) has been shown to be cytotoxic and produces inflammatory responses in humans. However, the cellular mechanisms underlying the neurotoxicity of fluoride are unclear. The present study aims to define a possible mechanism of NaF-induced neurotoxicity with respect to apoptosis and intracellular Ca2+ fluxes. Meanwhile, the cytoprotective role of taurine in intervention, the toxic effects of NaF on neurons, is also investigated. The primary mouse hippocampal neurons were incubated with 5.0, 10.0, 15.0, 20.0, and 40.0?mg NaF/L in vitro and Kunming mice were exposed to 0.7, 2.8, and 11.2?mg NaF/kg and 7.5 and 15.0?mg taurine/kg in vivo. Intracellular Ca2+ fluxes and apoptosis were assayed. Compared with the control, the significant differences of intracellular Ca2+ concentration and apoptotic peaks were found in 5.0–40.0?mg NaF/L groups in vitro (p?<?0.01) and in the groups of 0.7–11.2?mg NaF/kg in vivo (p?<?0.01). Instantaneously, taurine can minimize F-induced neurotoxicity significantly at doses of 7.5 and 15.0?mg/kg (p?<?0.01). The present study herein suggested that NaF could increase intercellular Ca2+ concentration leading to apoptosis. Meanwhile, taurine could minimize neurotoxicity caused by fluoride through decreasing intercellular Ca2+ concentration and cell apoptosis. 相似文献
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按国标法对16头新疆驴的驴乳进行牛磺酸质量浓度测定,结果表明:驴乳中牛磺酸的平均质量浓度为(1.35±0.34)mg/100 g,范围(0.72~1.91)mg/100 g,变异系数25.19%。不同驴乳样本间牛磺酸质量浓度差异较大。 相似文献
9.
取健康志愿者外周静脉血并分离血小板,采用随机分组的方式将血小板分成6组。通过检测血小板最大聚集率、膜表面CD62P及PAC-1阳性表达率,探讨不同浓度的牛磺酸(Tau)对苯并芘(BAP)体外诱导血小板聚集活化功能的影响。结果表明,血小板最大聚集率在二磷酸腺苷( ADP)和胶原诱导下各浓度BAP-Tau组与溶剂对照组之间比较差异均有统计学意义(P<0.01)。血小板膜表面CD62P、PAC-1表达率BAP-Tau高浓度组与溶剂对照组比较差异有统计学意义(P<0.01)。不同浓度的Tau均可拮抗BAP致血小板功能损伤的作用,且呈浓度梯度性变化。 相似文献
10.
Alan S. Wang Alessia Lodi Lee B. Rivera Jose L. Izquierdo‐Garcia Matthew A. Firpo Sean J. Mulvihill Margaret A. Tempero Gabriele Bergers Sabrina M. Ronen 《NMR in biomedicine》2014,27(11):1361-1370
The prognosis for patients with pancreatic cancer is extremely poor, as evidenced by the disease's five‐year survival rate of ~5%. New approaches are therefore urgently needed to improve detection, treatment, and monitoring of pancreatic cancer. MRS‐detectable metabolic changes provide useful biomarkers for tumor detection and response‐monitoring in other cancers. The goal of this study was to identify MRS‐detectable biomarkers of pancreatic cancer that could enhance currently available imaging approaches. We used 1H high‐resolution magic angle spinning MRS to probe metabolite levels in pancreatic tissue samples from mouse models and patients. In mice, the levels of lipids dropped significantly in pancreata with lipopolysaccharide‐induced inflammation, in pancreata with pre‐cancerous metaplasia (4 week old p48‐Cre;LSL‐KrasG12D mice), and in pancreata with pancreatic intraepithelial neoplasia, which precedes invasive pancreatic cancer (8 week old p48‐Cre LSL‐KrasG12D mice), to 26 ± 19% (p = 0.03), 19 ± 16% (p = 0.04), and 26 ± 10% (p = 0.05) of controls, respectively. Lactate and taurine remained unchanged in inflammation and in pre‐cancerous metaplasia but increased significantly in pancreatic intraepithelial neoplasia to 266 ± 61% (p = 0.0001) and 999 ± 174% (p < 0.00001) of controls, respectively. Importantly, analysis of patient biopsies was consistent with the mouse findings. Lipids dropped in pancreatitis and in invasive cancer biopsies to 29 ± 15% (p = 0.01) and 26 ± 38% (p = 0.02) of normal tissue. In addition, lactate and taurine levels remained unchanged in inflammation but rose in tumor samples to 244 ± 155% (p = 0.02) and 188 ± 67% (p = 0.02), respectively, compared with normal tissue. Based on these findings, we propose that a drop in lipid levels could serve to inform on pancreatitis and cancer‐associated inflammation, whereas elevated lactate and taurine could serve to identify the presence of pancreatic intraepithelial neoplasia and invasive tumor. Our findings may help enhance current imaging methods to improve early pancreatic cancer detection and monitoring. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献