大鼠口服灯盏花素的肠淋巴通道转运研究

建立清醒大鼠肠系膜淋巴管和颈静脉的双插管模型,以探索灯盏花素口服经肠淋巴通道的转运规律。采用HPLC法测定血浆和淋巴液中灯盏乙素浓度。双插管大鼠模型分别进行静注和口服灯盏花素的药动学实验。灯盏乙素静脉注射后存在从血液循环向肠淋巴系统的分布,肠淋巴累积转运量为(2.78±0.25)μg,是静注剂量的0.079 2%。灯盏乙素口服经肠淋巴通道12 h累积转运量为(0.92±0.08)μg,是口服剂量的0.008 3%;口服主要经门静脉通道吸收,绝对生物利用度为4.91%。灯盏乙素与乳糜微粒表面载脂蛋白的结合可能是其肠淋巴转运的主要形式。本研究为通过促进灯盏乙素肠淋巴转运而获得高生物利用度的灯盏花素脂质给药系统的研制提供了生物药剂学基础。     

高效液相色谱法测定灯盏乙素血药浓度及其脂质体大鼠药代动力学的评价

目的研究灯盏乙素脂质体及水剂在大鼠体内的血药浓度,考察大鼠灌胃给药后体内药代动力学参数。方法通过大鼠灌胃灯盏乙素水溶液和脂质体后,用高效液相色谱法测定不同时间点的血浆药物浓度,用DAS2.0软件对血药浓度数据拟合分析,比较药动学参数。结果灯盏乙素水剂和脂质体大鼠灌胃给药后,Cmax分别是(15.35±1.37)μg/mL和(22.04±1.67)μg/mL,AUC0-∞分别为(50.03±13.45)μg/(h·mL)和(80.96±15.26)μg/(h·mL),灯盏乙素包衣脂质体大鼠口服给药后药动学呈双室模型特征,与灯盏乙素水剂相比,其脂质体的灌胃AUC0-∞显著提高(P<0.01)。结论本高效液相色谱法对大鼠血浆灯盏乙素测定,稳定性、灵敏度及专属性强,灯盏乙素脂质体可显著提高灯盏乙素的生物利用度。     

酶解法与LC-MS-MS相结合研究灯盏乙素在健康人体内的药代动力学

目的建立β-葡萄糖醛酸苷酶解法与LC-MS-MS法相结合测定人体血浆中灯盏乙素的苷元,研究健康男性单剂量口服灯盏花素分散片的药代动力学。方法血浆样品经β-葡萄糖醛酸苷酶水解,甲醇蛋白沉淀,色谱柱为Agilent ZORBAX SB C18(2.1 mm×150 mm,5μm),运用乙腈-甲醇-水洗脱,多反应监测(MRM)灯盏乙素苷元([M-H]-,m/z285.0/136.8)和内标槲皮素([M-H]-,m/z 301.1/120.8)。12名健康男性单剂量口服灯盏花素分散片120 mg后,采用该方法测定血浆中灯盏乙素苷元,使用DAS 1.0软件处理数据,计算药代动力学参数。结果灯盏乙素苷元在4.01~513.38μg·L-1范围内线性良好,日内日间精密度小于7.22%,提取回收率大于84.23%。12名健康男性单剂量口服灯盏花素分散片120 mg后,以灯盏乙素苷元为检测对象的主要药动学参数为:Cmax(μg·L-1):159.97±58.14;AUC(0-19)(μg·L-1·h):1151.37±279.80;AUC(0-∞)(μg·L-1·h):1194.13±264.51;Tmax(h):6.33±1.67;T1/2(h):2.83±0.60。结论建立的酶解与LC-MS-MS相结合分析方法准确灵敏,适用于灯盏乙素人体内的药代动力学研究。     

高效液相-质谱联用法(HPLC-MS)测定灯盏乙素血药浓度及其临床药代动力学研究

目的:研究灯盏花素片在中国人体内的药代动力学。方法:2 0名健康志愿者单剂量口服12 0mg灯盏花素片,用高效液相 质谱联用法测定血浆中灯盏乙素总苷元。结果:本实验建立的血药浓度测定方法,血浆中杂质不干扰样品的测定,线性范围为0 .0 12 6～3.2 4mg·L-1;日内和日间精密度均小于12 .0 %。2 0名健康受试者单剂量口服灯盏花素片(12 0mg)后,主要药代动力学参数:Tmax =7.0±2 .3h、Cmax=0 .9±0 .5mg·L-1、AUC0 -tn =5 .6±1.6mg·h·L-1、AUC0 -∞=5 .8±1.6mg·h·L-1、MRT0 -tn=8.0±1.1h、MRT0 -∞=8.6±1.4h。结论:建立的LC MS法适用于灯盏乙素人体药代动力学研究。灯盏花素片口服药代动力学特点是达峰时间较长,约占受试者总人数4 5 %的药时曲线有双峰现象。     

灯盏花素在小鼠体内药物动力学研究

目的:研究灯盏花素在小鼠体内的药物动力学和绝对生物利用度。方法:采用固相萃取 高效液相色谱(SPE HPLC)法,测定小鼠静脉注射灯盏花素5 0mg·kg-1和灌胃15 0mg·kg-1后血浆灯盏乙素浓度,3p97程序处理数据。结果:小鼠静注灯盏花素后灯盏乙素的血浓 时间变化符合三房室模型,AUC、C0 和T1 2 β分别为12 .97±3.5 5mg·L-1·h、132 .2 3±39.90mg·L-1和4 .0 4±1.2 9h。灌胃后药物吸收很快,但血浓低。采用非房室模型法计算AUC为1.97±0 .5 3mg·L-1·h ,T1 2Ke 为3.4 1±1.2 3h。绝对生物利用度为5 .0 5 %。结论:灯盏花素经静注在小鼠体内的药代动力学符合三室模型。灌胃给药吸收快,但吸收差,绝对生物利用度低,且药时曲线变化不规则。     

灯盏乙素在家犬体内的药动学研究

目的　建立高效液相色谱法测定家犬血浆中灯盏乙素的浓度 ,研究灯盏乙素在家犬体内的药动学。方法　用高效液相色谱法测定 6只家犬静脉注射灯盏乙素后不同时间血浆中灯盏乙素的浓度 ,绘制药 -时曲线 ,计算药动学参数。结果　灯盏乙素的药 -时曲线符合三室模型 ,其T1 2 pi、T1 2 α和T1 2 β分别为 1.0 5± 0 .80min ,6 .99± 2 .76min和 5 1.6 1± 2 8.78min ;Vc为 880 .1± 5 0 8.3mL ;CL为 189.6± 5 3.8mL·min- 1 ;AUC0 90 和AUC0 ∞ 分别为 5 74 .4 3± 133.95 μg·min·mL- 1 和 5 99.34± 132 .0 0 μg·min·mL- 1 。结论　静脉注射给药后 ,血浆中灯盏乙素浓度迅速下降。灯盏乙素在家犬体内消除较快 ,提示临床给药方法或给药间隔时间的确定、制剂开发的剂型选择都应该考虑其T1 2 。     

灯盏花素缓释片在兔体内的绝对生物利用度

目的测定兔静注灯盏花素注射剂25 mg及兔口服灯盏花素缓释片120 mg后血浆中野黄芩苷的浓度,研究2种制剂的药动学参数和缓释片的绝对生物利用度。方法采用C_8固相萃取法预处理血浆样品,兔静注和口服灯盏花素后的血药浓度分别采用高效液相色谱-紫外检测法和高效液相色谱-质谱检测法测定。结果兔静注灯盏花素注射剂后的药-时曲线符合三室模型。兔口服灯盏花素缓释片后的药-时曲线难以用现有的房室模型拟合,6只兔的药-时曲线及药动学参数差异较大。经剂量校正,口服给药的绝对生物利用度F为(0.18±0.15)%。结论兔口服灯盏花素缓释片后的绝对生物利用度很低。     

灯盏花素β-环糊精包合物在大鼠体内的药物代谢动力学研究

目的 研究灯盏花素β-环糊精包合物在大鼠体内的吸收情况.方法 采用反相高效液相色谱法测定大鼠血浆中灯盏乙素质量浓度,比较大鼠口服灯盏花素β-环糊精包合物和灯盏花素市售片的平均药时曲线及药物代谢动力学参数.结果 灯盏花素β-环糊精包合物最高血药浓度为0.338μg/mL,普通片最高血药浓度为0.184 μg/mL,包含物的口服吸收率优于普通市售片.结论 该方法线性范围良好,准确、方便、可靠,取样量少,灵敏度可达0.025 μg/mL,尤其适用于动物体内药物代谢动力学研究.     

冰片对灯盏花素在大鼠体内药动学的影响

目的:观察冰片对灯盏花素在大鼠体内药动学的影响。方法:建立高效液相色谱(HPLC)方法测定大鼠血浆中灯盏乙素的浓度。大鼠尾静脉注射灯盏花素注射液(灯盏乙素24 mg.kg-1)及灯盏花素冰片注射液(灯盏乙素24 mg.kg-1 冰片0.96 mg.kg-1),用HPLC法测定大鼠给药后不同时间血浆灯盏乙素的浓度,BAPP数据处理软件计算药动学参数。结果:灯盏乙素在0.05~60μg.mL-1范围内线性良好(r=0.999 4)。灯盏花素与冰片配伍给药可使灯盏花素中灯盏乙素的药动学参数t1/2α,t1/2β和t1/2γ较单独给药时明显减小[t1/2α:(1.87±0.14)vs(3.46±0.45),P<0.01;t1/2β:(11.18±2.07)vs(14.74±2.89),P<0.05;t1/2γ:(53.31±8.21)vs(161.16±15.48),P<0.01],而K12较单独给药时明显增大[(0.120±0.042)vs(0.039±0.037),P<0.05]。结论:冰片可加快灯盏花素在大鼠体内的分布与消除。     

固相萃取前处理HPLC-MS法测定口服给药后家兔血浆中的灯盏乙素

目的建立灵敏、专属的HPLC-ESI-MS测定法, 用于测定家兔口服灯盏花素缓释片(2片 60 mg/片)后的血药浓度.方法该定量方法采用芦丁作内标,用固相萃取(SPE)进行样品前处理.以甲醇10 mmol·L-1醋酸铵水溶液(pH 8.0)梯度洗脱,流动相流速0.4 mL·min-1,柱温35 ℃,经过Zorbax Extend-C18 (150 mm×2.1 mm ID, 5 μm)色谱柱分离,电喷雾质谱检测器在负离子模式下检测灯盏乙素和芦丁.结果在2～200 ng·mL-1范围内灯盏乙素与内标峰面积与浓度线性关系良好,且准确度、精密度满足生物样品分析的要求.结论本实验建立的兔血浆中灯盏乙素的HPLC-MS分析方法灵敏度高,可用于口服给药后灯盏乙素的血药浓度测定.     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.