镧对小鼠肝脏中几种酶活性的影响

分别从体内作用和体外作用两个方面研究了镧对鼠肝脏中的胆碱脂酶、异柠檬酸脱氢酶、谷丙转氨酶活性的影响 ,同时用电感耦合等离子质谱 (ICP -MS)研究了镧在肝脏中的累积情况 .结果表明 :经尾静脉注射后镧在肝脏中有明显的累积现象 ,其累积量随给药剂量的增大而增加 ;镧对上述三种酶的活性均表现出低剂量激活 ,高剂量抑制的Hormesis效应     

稀土在鼠肝中的物种分布

采用 ICP-MS、微量蛋白层析分离技术 ,研究了长时间、低剂量混合稀土及短时间、高剂量硝酸镧分别对大鼠及小鼠作用后 ,稀土在鼠肝中的代谢累积及其物种分布 .结果表明 ,鼠肝中各稀土含量随给药剂量的增加而增大 ,其累积速度大小顺序为 La>Ce>Nd>Pr;经柱层析分离未得到与稀土特异结合的鼠肝蛋白 ;稀土可与多种鼠肝蛋白 (包括多种重要的酶 )结合 ,在一定条件下 ,稀土与其结合蛋白可发生解离     

高效液相色谱-四极杆/静电场轨道阱高分辨质谱法快速分析三子散的入血成分及代谢产物

蒙药三子散由诃子、川楝子、栀子3味药材等比例组成,其临床用药主要采用口服给药方式,药物在体内的吸收、分布、代谢、排泄过程与药物发挥药理作用和疗效的产生密切相关,因此考察灌胃给药后的入血成分有助于阐明三子散的药效物质基础。研究采用血清药物化学研究思路,将Wistar大鼠分成空白组和给药组,给药组给予三子散水提物,腹主动脉取血,离心制备血清样品,采用高效液相色谱-四极杆/静电场轨道阱高分辨质谱(HPLC-Q/Orbitrap HRMS),在SHIMADZU GIST C₁₈色谱柱(150 mm×4.6 mm, 5 μm)上进行色谱分离;以甲醇和0.1%(v/v)甲酸水溶液为流动相进行梯度洗脱,柱温30 ℃,流速0.5 mL/min,进样量10 μL,采用加热电喷雾电离(HESI)源,正、负离子同时扫描。通过比对三子散含药血清和空白血清的图谱差异,查阅数据库、各类成分体内代谢途径、三子散成分的相关文献,采用Xcalibur 3.0软件进行峰提取、峰匹配等质谱数据处理,结合Compound Discover 3.0软件对化合物代谢途径的预测分析和裂解规律的推断,解析三子散水提液经大鼠灌胃后血清中的原型成分和代谢产物。结果表明,在给药大鼠血清样品中鉴定出55种入血成分,其中41种原型成分,14种代谢产物。入血的原型成分主要为鞣质类、环烯醚萜类和小分子酚酸类。该研究较为全面地阐释了三子散水提液在大鼠血中的移行成分,有助于揭示三子散的药效物质基础,为该药的临床应用提供参考。     

二巯基丁二酸对~(210)铅组织分布和蛋白结合影响(摘要)

研究了二巯基丁二酸对铅的解毒作用。方法：小鼠iv210铅370kBq后，ig或ip二巯基丁二酸，剂量为1．0g·kg－1，用整体放射自显影术定位显示；大鼠210铅中毒后，用凝胶色谱法分离血清、肝、肾和尿，测定210铅与蛋白结合。结果：定位分布显示，对照小鼠肾脏210铅含量最高，肝、脾、肺、心、骨含量其次，脑内含量最低。给药后，大部分组织210铅含量明显减少。整体自显影片微光密度测定与相同部位组织用液门测定结果基本一致，大鼠血清和肝脏分离得到3个不同相对分子质量210铅蛋白复合物，肾脏仅有大分子210铅蛋白复合物，尿中主要为低相对分子质量非蛋白复合物。给药动物血清、肝脏和肾脏蛋白复合物与对照相似，但放射性含量低于对照，而尿中复合物210铅明显高于对照。结论：二巯基丁二酸对铅的解毒，减少了铅在体内各脏器中的沉积，以及与蛋白结合，促进其随尿液排出。     

立得益片对铅中毒小鼠(生殖系统、脑、血液、心脏)促排铅的作用

研究了立得益片对铅中毒小鼠促排铅的作用。给小鼠腹腔注射醋酸铅溶液染毒 7d ,建立铅中毒模型后 ,灌胃给药不同剂量立得益片及阳性对照药物EDTA ,极谱法测定不同时间生殖系统、脑、血液、心脏中的铅含量 ,观察及统计立得益片对铅中毒小鼠上述各脏器的促排铅作用。结果表明 ,铅中毒小鼠给药 6、 1 3d后脑、心脏、血液中的铅含量明显下降 ,生殖系统中仅卵巢和子宫中的铅含量在给药 1 3d后 ,立得益片高剂量组与模型对照组有显著性差异 (P <0 0 1 )。提示立得益片对铅中毒小鼠血液及脏器有明显促排铅作用 ,降低机体的铅负荷且存在时效、量效关系     

离子交换树脂纯化酪蛋白磷酸肽研究

通过单因素实验和正交试验确定了使用D-201型大孔强碱性阴离子交换树脂纯化酪蛋白磷酸肽(CPPs)的操作条件为：洗脱温度40℃、洗脱酸(HCI)浓度0．2mol／L、洗脱速度2．3ml／min、进样浓度2％(w／v)，进一步应用HPSEC技术分析考察了离子交换树脂纯化后含磷洗脱峰分子量分布情况，并计算了产品氮磷比与纯化收率．     

镧对仔鼠嗅感觉神经元分化中β—Ⅲ微管蛋白的作用

为观察发育期氯化镧暴露对仔鼠嗅觉功能及β-Ⅲ微管蛋白表达的影响,将16只Wistar孕鼠随机分为两组（对照组、氯化镧组）,对照组母鼠饮用蒸馏水,氯化镧组饮用0．25％氯化镧溶液;仔鼠出生后25d采用嗅觉迷宫试验检测仔鼠嗅觉功能的差异;于出生后28d采用免疫荧光和免疫印迹观察仔鼠β-Ⅲ微管蛋白在嗅上皮的表达变化。结果表明,氯化镧组仔鼠在嗅觉迷宫试验寻找食物的时间较对照组长,差异具有统计学意义（P〈0．05）;氯化镧组下调仔鼠嗅上皮β-Ⅲ微管蛋白在嗅感觉神经元的表达。提示镧暴露损害子代嗅觉功能,可能与镧损害嗅上皮β-Ⅲ微管蛋白的表达有关。     

异硫氰酸苯酯柱前衍生化反相高效液相法同时测定18种氨基酸

 建立了一种利用反相高效液相同时测定 18种氨基酸的方法。以正亮氨酸为内标物 ,异硫氰酸苯酯为柱前衍生剂 ,用C18柱在柱温 38℃下采用二元梯度洗脱 ,于 2 5 4nm波长处检测。氨基酸质量浓度在 3 5mg/L～ 5 5 6mg/L时 ,其峰面积与内标物峰面积的比值和氨基酸的质量浓度的线性相关系数 ,除胱氨酸 (0 96 2 )外均大于 0 99;18种氨基酸的加标回收率在 96 0 %～ 10 2 .4 %。信噪比为 2时 ,亮氨酸最低检测限为 0 5mg/L。应用该方法对小牛血去蛋白注射液中的游离氨基酸含量进行了测定 ,取得了满意的结果。     

新疆药桑叶多糖的分离纯化及结构研究

研究了新疆药桑叶多糖的分离纯化及初步的结构分析。采用DEAE-Cellulose-52及Sephadex G-200分离纯化药桑叶多糖,采用聚酰胺薄层层析及GC法测定药桑叶多糖的组成,凝胶过滤法测定其相对分子质量,红外光谱测定其苷键类型。粗多糖经DEAE-52分离得到6个多糖级分W1、W2、N1、N2、N3和N4,其中的4个级分W1、N1、N2和N4经Sephadex G-200纯化后,各个级分的洗脱峰均为单一对称峰。聚酰胺薄层法及GC法确定药桑叶多糖由葡萄糖、半乳糖、甘露糖、鼠李糖、阿拉伯糖及木糖等单糖组成。测得W1、N1、N2和N4的分子量分别为71 331Da,60 049Da,35 825Da和21 374Da。红外光谱中有典型的多糖吸收峰及α-型糖苷键。     

基于~1HNMR的代谢组学方法对大鼠砒霜给药后血清的研究

运用代谢组学方法研究了Wistar大鼠灌胃给药砒霜2和10 mg/kg剂量血清代谢的变化。通过核磁共振技术检测大鼠血清的代谢指纹图谱,然后利用主成分分析法分析空白组和砒霜给药组的代谢物差异,研究不同剂量砒霜在大鼠体内的急性生物效应。结果表明,砒霜对大鼠的急性靶向器官是肝脏,随着剂量增大,毒性增强;低剂量给药导致氧化应激,高剂量给药诱导细胞凋亡;低和高剂量给药均出现糖、氨基酸及脂质代谢紊乱,且能量代谢异常。     

流化床聚合反应器两种操作模式下乙烯共聚物的链结构与力学性能

采用制备型升温淋洗分级方法,对流化床聚合反应器在持液操作模式和冷凝态操作模式下生产的A、B两种乙烯/1-丁烯/1-己烯三元共聚物进行了分级,并结合多种分析手段对样品及其各级份进行了结构表征,同时测试对比了A、B两种聚乙烯样品的力学性能.结果表明,与冷凝态操作模式生产的聚乙烯样品B相比,持液操作模式下生产的聚乙烯样品A的拉伸屈服强度、拉伸断裂强度、断裂伸长率、冲击强度和雾度都比样品B优异.样品A的低温淋洗级份相对含量低于样品B,而其高温淋洗级份相对含量高于样品B;样品A低温淋洗级份的分子量略低于样品B,而其高温淋洗级份的分子量高于样品B;样品A的薄片晶含量和厚片晶含量都比样品B多,同时样品A的片晶厚度分布比样品B宽;样品A的总支化度以及每个级份的支化度都比样品B高,且样品A的支链在分子链间的分布比样品B宽,即样品A的支链比样品B的支链更倾向于生长在高分子量部分.通过以上表征分析,发现持液操作模式下生产的样品A比冷凝态操作模式下生产的样品B的物理使用性能更加优异,适合制备高性能的拉伸缠绕膜.     

Purification and characterization of hamster hepatic microsomal N,O-acetyltransferase.

A microsomal N,O-acetyltransferase which activates carcinogenic arylacetohydroxamic acids was purified 75-fold from hamster liver sequentially by anion exchange column chromatography, chromatofocusing, gel filtration, and hydroxyapatite column chromatography. The purified enzyme, AT-2, was a glycoprotein with a molecular weight of 60000 and a pI value of 5.4. The N-terminal amino acid sequence of AT-2 was: 60000 and a pI value of 5.4. The N-terminal amino acid sequence of AT-2 was: Asp-Ser-Pro-Ser-Pro-Ile-Arg-Asn-Thr-His-Thr-Gly-Gln-Val-Arg-Gly-Leu-Val- His- Lys-. This sequence was highly homologous to that of the form 2 carboxylesterase of rabbit liver, but not to that of major hepatic microsomal carboxylesterases of hamster and other species. AT-2 catalyzed the hydrolysis of 4-nitrophenyl acetate and the N,O-acetyltransfer of N-hydroxy-2-acetylaminofluorene. Both enzyme activities were strongly inhibited by paraoxon, but not by iodoacetamide. These results demonstrate that this N,O-acetyltransferase is a member of carboxylesterase (EC 3.1.1.1).     

Study of the metabolites of bencycloquidium bromide racemate, a novel anticholinergic compound, in rat bile by liquid chromatography-tandem mass spectrometry

A sensitive and specific liquid chromatographic-electrospray ionization (ESI) tandem ion trap mass spectrometric method has been developed for identification of bencycloquidium bromide (BCQB) and its metabolites in rat bile. Six healthy rats were administrated a single dose (3.0 mg kg(-1)) of BCQB by intraperitoneal (i.p.) injection. The bile were sampled from 0 h to 24 h and purified by using a C(18) solid- phase extraction (SPE) cartridge, then the purified bile samples were separated on a reversed-phase C(18) column using acetonitrile/40 mM ammonium acetate buffer (containing 0.1% formic acid) as mobile phase at gradient elution and detected by an on-line MS(n) detector. Identification and structural elucidation of the metabolites were performed by comparing the changes in molecular weight (Deltam) and full scan MS(n) spectra with those of the parent drug. Eight metabolites (such as hydroxylated and oxidized metabolites) and the parent drug were found in rat bile. Eight metabolites of BCQB were identified and hydroxylated metabolites were the major metabolites. The metabolic pathways of BCQB in vivo are proposed for the first time.     

Chromatographic Properties of Metallothioneins on a Gel Permeation Column: Changes Induced by Replacement of Cadmium with Cuprous and Cupric Ions

Abstract

In vitro experiments were conducted to find whether or not a similar elution profile to rat kidney metallothionein with high copper content was obtained on a gel permeation column by replacement of cadmium and/or zinc in rat liver metallothionein with copper. Stepwise replacement of cadmium in rat liver metallothionein with cuprous ion did not cause any shifts of retention times from those of the original proteins on a gel permeation column (SW 3000 column). In contrast to cuprous ion, stepwise replacement of cadmium with cupric ion induced shifts of retention times to larger values than the original ones for the two isometallothioneins on a SW column. Replacement of zinc in zinc-thionein with cupric ion but not with cuprous ion caused a retardation of elution volume on a Sephadex G-75 column. The decreases of cadmium peaks were accompanied by the increases of copper peaks in the case of replacement of cadmium in metallothionein with cuprous ion. Although stepwise decreases of cadmium peaks were observed by the replacement of cadmium in metallothionein with cupric ion, concomitant increases of copper peaks were not observed. Although the relative peak heights of isometallothionein peaks were different from those of rat kidney metallothionein, the third peak with the same retention time as that of rat kidney metallothionein was observed for the replacement of cadmium with cupric but not with cuprous ion.     

In vivo metabolism study of polygalic acid in rat using HPLC-ESI-MSn

A very simple and direct method has been established for the determination of polygalic acid and its metabolites in rat urine based on HPLC coupled with electrospray ionization multi-stage tandem mass spectrometry (HPLC-ESI-MS(n)). The rats were administered a single dose (100 mg/kg) of polygalic acid by oral gavage. The urine samples were collected and purified through a C(18) solid-phase extraction cartridge, and then these pretreated samples were injected into a reversed-phase C(18) column with a gradient elution program, whereas acetonitrile-0.5% aqueous formic acid was used as mobile phase and detected by an on-line MS/MS system. As a result, the parent drug and its four metabolites were identified and characterized in rat urine for the first time by comparing their changes in molecular mass (ΔM), retention times and full-scan MS(n) spectra with those of the parent drug. A possible metabolic pathway of polygalic acid was investigated and proposed. More importantly, the results demonstrated that the newly developed method (HPLC-ESI-MS(n)) was sensitive, simple and suitable for the determination of polygalic acid and its metabolites in biological samples.     

Rapid Purification of the Unstable Enzyme Carbamoyl Phosphate Synthase by High Pressure Liquid Chromatography

Abstract

Extracts of soluble proteins obtained from rat liver mitochondria by freeze-thawing and subsequent diafiltration were fractionated by HPLC on a I 250 protein column. The column was eluted either with 0.05 M phosphate buffer pH 6.85 or 0.1 M acetate buffer pH 7.15. Specific fractions obtained by elution with either phosphate or acetate buffer showed a 6.1-fold or 5.5-fold increase in the specific activity of Carbamoyl phosphate synthase when compared with that of crude mitochondrial preparations. The purification and the molecular weight of carbamoyl phosphate synthase were verified by sodium dodecyl sulphate-polyacrylamide gel electrophoresis.     

Enhancement by Glycyrrhizae Radix of hepatic metabolism of hypaconitine,a major bioactive and toxic component of Aconiti Laterlis Radix,evaluated by HPLC‐TQ‐MS/MS analysis

Glycyrrhizae Radix (GR) is often prescribed together with Aconiti Laterlis Radix (ALR) (a so‐called compatible drug pair) in traditional Chinese medicinal practice to reduce toxicity of ALR. However, the mechanisms involved remain to be addressed. In this study, the metabolic interactions between GR–ALR drug pair were investigated for the first time. First, an HPLC‐TQ‐MS/MS method was developed to analyze hypaconitine, a major bioactive and toxic component of ALR, in rat liver S9. Then the in vitro metabolic rates of hypaconitine by different rat liver S9 were compared using the established method. The experiments were designed in four groups: pure hypaconitine (group I) and ALR extract (group II) incubated with liver S9 of normal rats, and pure hypaconitine (group III) and ALR extract (group IV) incubated with liver S9 of GR‐pretreated rats. When incubated for more than 4 h, the metabolic rates of hypaconitine in group III were significantly higher than those in group I, and when incubated for more than 2 h, the metabolic rates of hypaconitine in group IV were significantly higher than those in group II, suggesting that GR can enhance metabolic rate of hypaconitine, the mechanism of which might be related to hepatic metabolizing enzyme induction by GR. Copyright © 2012 John Wiley & Sons, Ltd.     

热水管材用乙烯-丙烯无规共聚树脂的结构表征

近几年发展起来的热梯度淋洗分级法(TREF)在研究高结晶聚烯烃的聚合反应机理方面表现出优越性.TREF是根据结晶性聚合物的结晶度进行分级的一项分析和制备技术.Desreux首先提出根据结晶度进行分级的思想[1],而Shirayama首次采用TREF方法对低密度聚乙烯完成分级[2].除聚乙烯外,TR