生物样品中莱曼宁的气相色谱测定及其在动物体内的药代动力学

本文采用气相色谱法分离并测定了生物样品中莱曼宁的浓度,研究了莱曼宁在动物体内的吸收、分布和排泄过程。小鼠ig莱曼宁后的吸收速率常数为0.73h~(-1)。大鼠4h的胆汁排泄量仅为给药量的0.6％,大鼠尿中32h排泄量为给药量的13.3％。大鼠iv给药后体内过程符合二房室特征。大鼠体内分布以肾脏最高,其次为脾、肝、心、脑,外周组织如脂、肌含量较少。莱曼宁与兔血浆蛋白的结合率为49.2％。     

齐墩果酸在大鼠体内的药动学及组织分布

目的建立HPLC-MS/APCI法测定SD大鼠血中及组织中齐墩果酸浓度分析方法,并对其在大鼠体内的药动学、组织分布及血浆蛋白结合率进行研究.方法全血采用甲醇沉淀蛋白,血浆及组织匀浆采用有机溶剂提取的方法分别处理样品,HPLC-MS/APCI法测定.色谱柱Thermo Hypersil GOLD C18柱(150 mm×4.6 mm,5 μm);流动相为甲醇-水(含1‰甲酸)(85∶15);流速为1.0 mL·min-1;柱温为40℃.结果SD大鼠一次灌胃给予齐墩果酸后血药浓度-时间曲线呈一室模型,半衰期t1/2为(1.10±0.20)h.齐墩果酸在组织脏器的浓度分布特点是C肺＞C脾＞C肾＞C心＞C肝＞C脑,血浆蛋白结合率约为87%.结论SD大鼠灌胃给予齐墩果酸混悬剂后,其体内药动学过程符合单室模型一级吸收,药物进入体内后迅速分布,消除也较快;组织中以肺中浓度最高,脑中最低;齐墩果酸有较高的血浆蛋白结合率.     

同位素标记示踪法测定G蛋白竞争性抑制肽-27在动物体内的分布与排泄

目的：利用同位素标记示踪法研究G蛋白竞争性抑制肽（GCIP）-27在动物体内的分布和排泄。方法：^125I-GCIP采用Iodogen法标记，按组织器官直接测定法和TCA沉淀法进行体内分布实验，以每毫克组织器官的^125I-GCIP放射性计数表示GCIP在小鼠体内的分布；以不同时间段大鼠胆汁、尿、粪及小鼠的尿、粪放射性总排泄量占给药量放射性的百分比表示其在体内的排泄。结果：GCIP-27在小鼠体内分布广泛，其中肾、血管、胃、肺、心、小肠等组织分布较高，肌肉、脂肪等组织相对较低，脑最低。大鼠72h粪、尿、胆汁原形药物排泄量分别为给药量的26．13％，0．95％和4．12％。小鼠72h粪、尿原形药物排泄量分别为给药量的27，92％，0．84％。结论：GCIP-27在小鼠体内广泛分布，主要经尿液排泄，肾为主要排泄器官。     

国产阿齐红霉素在大鼠的组织分布及与正常人血浆蛋白结合率研究

对阿齐红霉素在大鼠的组织分布及与正常人血浆蛋白结合率进行研究，结果表明：阿齐红霉素在体内能很快分布于大多数脏器和组织中，并较长时间内保持较高的药物浓度。蛋白结合率测定结果表明：阿齐红霉素是一种血浆蛋白结合率较低的药物。     

恩其明醋酸盐的药代动力学研究

目的：研究恩其明醋酸盐（ＡＴ１８４０）在大鼠体内的药代动力学。方法：荧光检测法。结果：大鼠静注后，其体内的血药浓度－时间曲线符合二室开放模型。其分布相Ｔ１２α为０．５７ｍｉｎ，消除相Ｔ１２β为５．５１ｍｉｎ。大鼠ｉｖＡＴ１８４０后，组织中的药物浓度，以肺、肾浓度最高，肝、卵巢、心、脾、胃次之，肌肉、脂肪、脑中最低。尿中排泄量２４ｈ内占总给药量的２３．２８％；胆汁和粪中分别约为给药量的３６．４６％和１．７９％。ＡＴ１８４０与血浆蛋白的结合率６８．５％～７３．９％。结论：ＡＴ１８４０是一个血浆半衰期短，并有组织分布选择性的药物。     

间尼索地平在大鼠体内的组织分布、排泄及血浆蛋白结合率的测定

建立了HPLC法测定生物样品中间尼索地平的含量，并研究了其在大鼠体内的组织分布、排泄及血浆蛋白结合率等特征。以尼莫地平为内标，样品采用液-液萃取。采用C18柱，流动相为乙腈-20mmol／LKH2PO4溶液（60：40），检测波长237nm。间尼索地平在2～1000ng／ml范围内，线性关系良好。间尼索地平在大鼠体内分布广泛，经粪便及胆汁的排泄量均较少，而尿中则未检出药物原型，间尼索地平的血浆蛋白结合率达97％以上。     

口服川芎挥发油后小鼠体内藁本内酯的组织分布特性

目的：建立藁本内酯的RP-HPLC分析方法，并应用于藁本内酯在小鼠体内各组织的分布研究。方法：生物样品经过正己烷萃取浓集后，以尼莫地平为内标，用Kromasil C18柱（150mm×4．6mm，5μm）进行分析，以乙腈-10％异丙醇水溶液（58：42）为流动相，流速1．0mL／min，在324nm处进行检测。结果：藁本内酯与内标的保留时间分别为7．2min和5．9min，藁本内酯在各组织中一定浓度范围内线性关系良好，各组织中低、中、高浓度蒿本内酯的回收率及精密度均符合方法学要求。藁本内酯在小鼠主要效应器官中浓度分布如下：c肺〉c心〉C脑，在主要消除器官中c肝〉c脾〉c肾。藁本内酯在肺和脾脏中分布较多。结论：本方法方便、准确、可靠、可用于藁本内酯的体内分析研究。     

7-乙基-10-羟基喜树碱聚合物胶束的肿瘤靶向性研究

目的研究7-乙基-10-羟基喜树碱/聚乙二醇-聚天冬氨酸聚合物胶束(7-ethyl-10-hydroxycamptothecin/polyethylene glycol-polyaspartic acid polymer micelles,SN-38/PEG-pasp)在荷瘤小鼠体内的组织分布特点。方法采用LC-MS法测定荷瘤小鼠血浆和组织中7-乙基-10-羟基喜树碱(7-ethyl-10-hydroxycamptothecin,SN-38)的质量浓度,并用SPSS13.0统计学软件对测定的数据进行分析。结果药物在肿瘤组织中相对摄取率(r_e)达到10,远远高于其他组织,除去肝其余组织作为非靶向组织时,肿瘤的靶向效率(t_e)均大于1,呈现出明显的肿瘤靶向特征,胶束组药物在体内质量浓度排布顺序:肿瘤>肝>肺>脾>肾>心>血。结论 SN-38/PEG-pasp在肿瘤组织中药物浓度明显高于除肝脏外的其他各组织,具有明确的肿瘤靶向性。     

抗生素89－07在大鼠体内组织分布及与正常人血浆蛋白结合率研究

本文报道抗生素８９－０７在大鼠体内组织分布及与人血浆蛋白结合率，并与庆大霉素作比较，以了解抗生素８９－０７与庆大霉素在以上特性中的差异，对其进行药理学评价。结果表明：抗生素８９－０７和庆大霉素在大鼠体内各组织中以肾脏中药物含量最高，３ｍｉｎ时分别为９．４８±２．１７和６．２１±３．１０μｇ／ｇ，３０ｍｉｎ分别为９．７５±２．４５和１０．４５±３．３３μｇ／ｇ，２４０ｍｉｎ分别为１２．２７±７．３４和１３．８５±７．１７μｇ／ｇ。另外还测定了脑、心、胃肠道、胰、脾、肝、生殖腺、肌肉、脂肪和血中的浓度。抗生素８９－０７与人血浆蛋白结合率为２３．２１％±１．５３％；庆大霉素为２５．５１％±１．０２％，两者间无显著性差异（Ｐ＞０．０５）。由研究结果可以看出，抗生素８９－０７在大鼠体内组织分布及与正常人血浆蛋白结合率与庆大霉素相似。     

13-甲基豆蔻酸在大鼠体内的药代动力学研究

目的　研究 1 3 -甲基豆蔻酸在大鼠体内的药代动力学。方法　用毛细管柱气相色谱法测定生物样品中的原形药物浓度 ,在大鼠体内进行血浆药代动力学、分布、排泄及血浆蛋白结合实验。结果　大鼠 ig1 3 -甲基豆蔻酸 40 0 ,80 0 ,1 2 0 0 mg· kg-1后 ,拟合的血药浓度 -时间曲线符合二室模型 ,t1/2α 为 2 .3 1 3～ 2 .843 h,t1/2β 为5 .0 99～ 6 .3 3 9h;tpeak 为 2 .2 1 5～ 2 .76 6 h;血浆蛋白结合率大于 85 .80 %。药物在大鼠体内分布广泛 ,其中心、肺、脾、肝等组织浓度较高 ,肌肉、脂肪等组织相对较低。 2 4 h粪、尿、胆汁原形药物排泄量分别为给药量的1 3 .77% ,0 .0 0 3 2 %和 0 .0 2 1 4%。结论　 1 3 -甲基豆蔻酸在大鼠体内吸收快 ,达峰时间短 ,组织分布广泛 ,血浆蛋白结合率高 ;有部分原形药物从粪便排泄     

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.

     

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.     

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.     

2-(Acetoxyphenyl)-(Z)-styryl sulfides as cyclooxygenase inhibitors

2-(Acetoxyphenyl)-(Z)-styryl sulfides are described as selective cyclooxygenase-2 (COX-2) inhibitors, useful for treating inflammation and COX-2-mediated disorders including neoplasia. 2-(Acetoxyphenyl)-(Z)-styryl sulfide is claimed to be the most potent COX inhibitor in the series with a COX-2 selectivity ratio of 33. This compound is also claimed to be superior to celecoxib (Celebrex^®, Pfizer) in inhibiting cell growth of colorectal carcinoma cells. In this evaluation, the COX inhibitory activity of this compound is compared to that previously disclosed for diarylheterocycles and 2-(acetoxyphenyl)alkyl sulfides. The validity of the DLD-1 cell line in the growth inhibition studies is questioned based on recent literature reports indicating the lack of COX-2 expression in this cell line.     

Sleep-disordered breathing with chronic opioid use

Chronic opioid use for pain relief or as substitution therapy for illicit drug abuse is prevalent in our societies. In the US, retail distribution of methadone and oxycodone has increased by 824 and 660%, respectively, between 1997 and 2003. μ-Opioids depress respiration and deaths related to illicit and non illicit chronic opioid use are not uncommon. Since 2001 there has been an emerging literature that suggests that chronic opioid use is related to central sleep apnoea of both periodic and non-periodic breathing types, and occurs in ～ 30% of these subjects. The clinical significance of these sleep-related abnormalities are unknown. This review addresses the present knowledge of control of ventilation mechanisms during wakefulness and sleep, the effects of opioids on ventilatory control mechanisms, the sleep-disordered breathing found with chronic opioid use and a discussion regarding the future research directions in this area.     

Drug targets for cognitive enhancement in neuropsychiatric disorders

The investigation of novel drug targets for treating cognitive impairments associated with neurological and psychiatric disorders remains a primary focus of study in central nervous system (CNS) research. Many promising new therapies are progressing through preclinical and clinical development, and offer the potential of improved treatment options for neurodegenerative diseases such as Alzheimer's disease (AD) as well as other disorders that have not been particularly well treated to date like the cognitive impairments associated with schizophrenia (CIAS). Among targets under investigation, cholinergic receptors have received much attention with several nicotinic agonists (α7 and α4β2) actively in clinical trials for the treatment of AD, CIAS and attention deficit hyperactivity disorder (ADHD). Both glutamatergic and serotonergic (5-HT) agonists and antagonists have profound effects on neurotransmission and improve cognitive function in preclinical experiments with animals; some of these compounds are now in proof-of-concept studies in humans. Several histamine H3 receptor antagonists are in clinical development not only for cognitive enhancement, but also for the treatment of narcolepsy and cognitive deficits due to sleep deprivation because of their expression in brain sleep centers. Compounds that dampen inhibitory tone (e.g., GABA_A α5 inverse agonists) or elevate excitatory tone (e.g., glycine transporter inhibitors) offer novel approaches for treating diseases such as schizophrenia, AD and Down syndrome. In addition to cell surface receptors, intracellular drug targets such as the phosphodiesterases (PDEs) are known to impact signaling pathways that affect long-term memory formation and working memory. Overall, there is a genuine need to treat cognitive deficits associated with many neuropsychiatric conditions as well as an increasingly aging population.