不同浓度吲哚乙酸对小白菜硫代葡萄糖苷的影响--测试文章

以不同浓度（0,2 mg·L^-1,5 mg·L^-1,10 mg·L^-1,20 mg·L^-1）吲哚乙酸（IAA）对小白菜进行处理,分析其对小白菜生长和硫代葡萄糖苷（硫苷）含量的影响。结果表明,随着IAA处理浓度的提高,显著增加了小白菜地上部的鲜重,但增幅有所降低。与对照相比,IAA处理浓度为5～20 mg·L^-1时,显著诱导了总脂肪族硫苷、总吲哚族硫苷和总硫苷含量的提高,而IAA处理均显著提高了芳香族2-苯乙基硫苷的含量。对单个硫苷来说,在IAA处理浓度为5～20 mg·L^-1时,5-甲基亚磺酰戊基硫苷和3-丁烯基硫苷含量得到显著提高;而4-戊烯基硫苷、吲哚-3-甲基硫苷和4-甲氧基吲哚-3-甲基硫苷在外源IAA处理下,呈现先增加后降低的趋势,其中4-戊烯基硫苷在较低IAA处理浓度下（2 mg·L^-1）即显著高于对照;另外,1-甲氧基吲哚-3-甲基硫苷随着IAA处理浓度的增加呈现递增趋势。此外,随IAA处理浓度的增加,总脂肪族硫苷相对百分含量有增加的趋势,但总吲哚族硫苷相对百分含量呈递减趋势,而芳香族硫苷呈现先增加后降低的趋势。可见,对于7种硫苷来说,不同IAA处理浓度下有不同的响应,具有一定的浓度效应。     

Monomethylarsonous acid inhibited endogenous cholesterol biosynthesis in human skin fibroblasts

Human exposure to arsenic in drinking water is a widespread public health concern, and such exposure is known to be associated with many human diseases. The detailed molecular mechanisms about how arsenic species contribute to the adverse human health effects, however, remain incompletely understood. Monomethylarsonous acid [MMA(III)] is a highly toxic and stable metabolite of inorganic arsenic. To exploit the mechanisms through which MMA(III) exerts its cytotoxic effect, we adopted a quantitative proteomic approach, by coupling stable isotope labeling by amino acids in cell culture (SILAC) with LC-MS/MS analysis, to examine the variation in the entire proteome of GM00637 human skin fibroblasts following acute MMA(III) exposure. Among the ~ 6500 unique proteins quantified, ~ 300 displayed significant changes in expression after exposure with 2 μM MMA(III) for 24 h. Subsequent analysis revealed the perturbation of de novo cholesterol biosynthesis, selenoprotein synthesis and Nrf2 pathways evoked by MMA(III) exposure. Particularly, MMA(III) treatment resulted in considerable down-regulation of several enzymes involved in cholesterol biosynthesis. In addition, real-time PCR analysis showed reduced mRNA levels of select genes in this pathway. Furthermore, MMA(III) exposure contributed to a distinct decline in cellular cholesterol content and significant growth inhibition of multiple cell lines, both of which could be restored by supplementation of cholesterol to the culture media. Collectively, the present study demonstrated that the cytotoxicity of MMA(III) may arise, at least in part, from the down-regulation of cholesterol biosynthesis enzymes and the resultant decrease of cellular cholesterol content.     

Cellular energetics and glutathione status in NRK-52E cells: toxicological implications

Cellular energetics and redox status were evaluated in NRK-52E cells, a stable cell line derived from rat proximal tubules. To assess toxicological implications of these properties, susceptibility to apoptosis induced by S-(1,2-dichlorovinyl)-L-cysteine (DCVC), a well-known mitochondrial and renal cytotoxicant, was studied. Cells exhibited high activities of several glutathione (GSH)-dependent enzymes, including gamma-glutamylcysteine synthetase, GSH peroxidase, glutathione disulfide reductase, and GSH S-transferase, but very low activities of gamma-glutamyltransferase and alkaline phosphatase, consistent with a low content of brush-border microvilli. Uptake and total cellular accumulation of [14C]alpha-methylglucose was significantly higher when cells were exposed at the basolateral as compared to the brush-border membrane. Similarly, uptake of GSH was nearly 2-fold higher across the basolateral than the brush-border membrane. High activities of (Na(+)+K(+))-ATPase and malic dehydrogenase, but low activities of other mitochondrial enzymes, respiration, and transport of GSH and dicarboxylates into mitochondria were observed. Examination of mitochondrial density by confocal microscopy, using a fluorescent marker (MitoTracker Orange), indicated that NRK-52E cells contain a much lower content of mitochondria than rat renal proximal tubules in vivo. Incubation of cells with DCVC caused time- and concentration-dependent ATP depletion that was largely dependent on transport and bioactivation, as observed in the rat, on induction of apoptosis, and on morphological damage. Comparison with primary cultures of rat and human proximal tubular cells suggests that the NRK-52E cells are modestly less sensitive to DCVC. In most respects, however, NRK-52E cells exhibited functions similar to those of the rat renal proximal tubule in vivo.     

电针对大鼠脑出血模型海马组织氨基酸含量的影响

目的 :观察不同电针对大鼠脑出血模型海马组织氨基酸含量的影响 ,探讨电针对脑出血大鼠保护作用的可能机制。方法 :选择胶原酶加肝素联合注射法诱导脑出血大鼠模型 ,采用反相高效液相色谱荧光法观察电针不同穴位对大鼠海马氨基酸含量的影响。结果 :造模后模型组海马组织兴奋性氨基酸 (ASP、Glu)和抑制性氨基酸 (GABA)明显升高 ,存在着兴奋性氨基酸 (EAA) /抑制性氨基酸 (IAA)平衡失调。针水组能降低造模所致的Glu和GABA的升高 ,和模型组比有显著性差异 (P <0 .0 5) ,而对ASP的降低作用不明显 ,和模型组比无显著性差异 (P >0 .0 5) ;针风组能降低造模所致的ASP和Glu的升高 ,和模型组比有显著性差异 (P <0 .0 5) ,而对GABA的降低作用不明显 ,和模型组比无显著性差异 (P >0 .0 5)。结论 :针水组、针风组能抑制不同兴奋性氨基酸(Glu、ASP)的释放 ,纠正兴奋性氨基酸 (EAA) /抑制性氨基酸 (IAA)失衡 ,从而达到减轻脑出血后脑组织损害的作用。     

遮荫影响半夏不同器官IAA含量及其性状变化的应用研究

 目的研究遮荫对半夏不同器官中IAA含量及其形状变化的影响。方法利用完全随机设计对遮荫半夏和未遮荫半夏不同生长发育阶段块茎、珠芽和叶片中IAA的含量变化进行测定。结果遮荫对块茎和珠芽的生长均有不同程度的促进作用,对叶片的叶形改变和叶面积的增大也有显著的相关性。结论大田栽培中,随着光照的不断加强,可以适当的逐渐增加半夏遮荫的力度,但最高遮荫率不宜超过40%。     

γ射线增强喉癌细胞hTERTp启动子活性研究

目的 探讨γ射线对喉癌细胞中端粒酶逆转录酶基因启动子(hTERTp)活性的影响,以及通过射线增强hTERTp下游基因表达的可行性。方法 将含hTERTp的质粒转染细胞,采用报告基因评价启动子活性,通过RT-PCR和酶活性检测观察射线作用下hTERTp调控辣根过氧化物酶(HRP)的表达,克隆形成实验评价射线对phTERTp-HRP/IAA杀伤和放射增敏作用的影响。结果 在Hep-2细胞中,6 Gyγ射线照射后hTERTp活性是0 Gy照射后的2.96倍,在Hep-2R细胞中是1.60倍。质粒phTERTp-HRP转染Hep-2和Hep-2R细胞后,6 Gy照射组的HRP mRNA分别增高2.1和1.1倍,酶活性分别增高2.54和1.23倍。6 Gy联合吲哚乙酸(IAA)组Hep-2细胞的存活分数为1.3%,Hep-2R细胞的存活分数为3.5%,比对照组明显降低(F=234.280和F=357.148,P值均<0.01)。6Gy联合IAA组与IAA组相比,放射增敏比SER_<sub>SF2分别为1.52(Hep-2)和1.68(Hep-2R),存活曲线的参数α分别为0.416、0.099(Hep-2)和0.356、0.090(Hep-2R)。结论 γ射线可以增强不同放射敏感性喉癌细胞hTERTp活性,增强下游基因表达。射线联合phTERTp-HRP/IAA对喉癌细胞具有更加明显的杀伤和放射增敏作用。     

外源性胰岛素致自身免疫性低血糖一例报告

报告一例使用人胰岛素后出现自身免疫性低血糖患者,测定IAA(+),停胰岛素改为阿卡波糖口服后,低血糖发作减轻.