7—溴化乙氧苯四氢巴马汀对豚鼠心室肌细胞电压依赖性通道电流…

目的：研究７－溴化乙氧苯四氢巴马汀（ＥＢＰ）对电压敏感通道电流的影响，方法：在豚鼠心室肌细胞进行全细胞电流钳和电压钳记录，结果：ＥＢＰ３０μｍｏｌ．Ｌ＾－１可使单细胞ＡＰＤ９０从４３０±４７ｍｓ延长至５１４±６１ｍｓ（Ｐ〈０．０５，ｎ＝５）。电压钳研究表明ＥＢＰ可依剂量也抑制１Ｋ及其尾电流，而对１ｋ１，ｌｃａ和ｌＮａ无明显作用，结论：以上结果提示选择性地抑制ｌＫ从而延长动作电位时程，可能是ＥＢＰ抗     

Mechanisms of artemisinin antiarrhythmic action

采用全细胞电压钳技术,以确定青蒿素对分离的豚鼠心室肌细胞和狗的浦肯野纤维钾离子电流的影响．在豚鼠心室肌细胞,青蒿素呈浓度依赖关系显著降低内向整流钾电流〔ＩＫ１,膜电位为－１００ｍＶ时,ＩＣ５０为（７．２±０．８）μｍｏｌ·Ｌ－１〕,且这种抑制作用不呈现频率依赖性．５０μｍｏｌ·Ｌ－１的青蒿素降低延迟整流钾电流（ＩＫ）：时间依赖性外向钾电流（ＩＫｓｔｅｐ）在膜电位为＋４０ｍＶ时减少（３８±１０）％．尾电流步阶分析提示,ＩＫ的快组分（ＩＫｒ）和慢组分（ＩＫｓ）均被抑制．在犬浦肯野纤维,青蒿素明显抑制瞬时外向钾电流（Ｉｔｏ）,ＩＣ５０为（４．２±０．３）μｍｏｌ·Ｌ－１．实验结果表明,青蒿素以相似效率抑制ＩＫ１,Ｉｔｏ和ＩＫ,其抗心律失常作用可能与抑制ＩＫ１,Ｉｔｏ,ＩＫｒ和ＩＫｓ有关．     

Artemisinin blocks activating and slowly activating K~ current in guinea pig ventricular myocytes

目的：研究青蒿素（Ａｒｔ）对豚鼠心室肌细胞外向整流钾电流的作用．方法：以全细胞膜片箝技术观察Ａｒｔ对快速延迟整流钾电流（ＩＫｒ）和缓慢延迟整流钾电流（ＩＫｓ）的作用．结果：Ａｒｔ剂量依赖性抑制时间依赖性外向钾电流（ＩＫｓｔｅｐ）和ＩＫｔａｉｌ．Ａｒｔ５０μｍｏｌ·Ｌ－１在＋４０ｍＶ时，使ＩＫｓｔｅｐ从３８７±４６ｐＡ减少到２４０±４８ｐＡ，ＩＫｔａｉｌ从２９９±３０ｐＡ减少到１３０±３８ｐＡ．结论：Ａｒｔ抑制外向钾电流的两种成分ＩＫｓ和ＩＫｒ．     

7－溴化乙氧苯四氢巴马汀抑制外向钾电流和尾电流

应用膜片钳封接技术，对中药改构物７－溴化乙氧苯四氢巴马汀（ＥＢＰ）抗心律失常作用机理进行了研究。发现ＥＢＰ明显抑制了豚鼠单个细胞的延迟外向钾电流（ＩＫ）和外向尾电流，这一作用亦具浓度和频率依赖性，ＥＢＰ１０μｍｏｌ·Ｌ－１使ＩＫ从给药前的０．８８ｎＡ减少到０．６７ｎＡ，使尾电流从给药前的０．３６０ｎＡ减少到０．１１０ｎＡ。在膜电位－２０ｍＶ到＋６０ｍＶ区间作用较强。ＥＢＰ对ＩＫ１和钙电流影响不显著。揭示该药抗心律失常主要机理为抑制电压依赖性外向钾电流和尾电流。     

Effects of norepinephrine and isopentenyladenosine on Na~ /Ca~(2 ) exchangecurrents in isolated guinea pig ventricular myocytes

目的：研究去甲肾上腺素（ＮＥ）和异丙肾上腺素（Ｉｓｏ）对Ｎａ＋／Ｃａ２＋交换电流的影响及受体调控机制．方法：应用全细胞电压钳技术的斜坡脉冲程序，测定离体豚鼠心肌细胞准稳态电流电压关系曲线．结果：ＮＥ０００５，００５和５μｍｏｌ·Ｌ－１分别使膜电位＋５０ｍＶ时的Ｎｉ２＋敏感电流增加２９％±９％，７２％±１１％和１２０％±３１％；Ｉｓｏ１５，１５０和１５００ｎｍｏｌ·Ｌ－１分别使该电流增加２８％±２８％，５６％±１３％和１０２％±１２％．ＮＥ和Ｉｓｏ的这种增强效应能被普萘洛尔１０μｍｏｌ·Ｌ－１完全阻断，而酚妥拉明５０μｍｏｌ·Ｌ－１无此作用．结论：ＮＥ和Ｉｓｏ通过兴奋心脏β肾上腺素受体使Ｎａ＋／Ｃａ２＋交换电流增加．     

绞股蓝总皂甙对单个豚鼠心室肌细胞的钙、钠、钾电流及动作电位的影响

目的研究绞股蓝总皂甙（ＧＰ）对成年豚鼠单个心室肌细胞的动作电位（ＡＰ）、Ｌ－型钙通道电流（ＩＣａ）、快钠通道电流（ＩＮａ）以及内向整流钾通道电流（ＩＫ１）的影响。方法膜片钳全细胞记录。结果５０ｍｇＬ－１ＧＰ能使动作电位时程（ＡＰＤ９０）由给药前的（７０８±２４）ｍｓ缩短到给药后的（３９６±１６）ｍｓ（Ｐ＜０．０１），抑制率５８．１％，动作电位幅值（ＡＰＡ）由给药前的（１２１±７．２）ｍＶ降到给药后的（８６±８．６）ｍＶ（Ｐ＜０．０１），抑制率２４．１％，静息膜电位无明显影响；５～５０ｍｇＬ－１的ＧＰ能浓度依赖性阻滞ＩＣａ和ＩＮａ，但对ＩＫ１无明显影响。结论ＧＰ对缺血心肌的保护作用在于减少“钙超载”和抑制异常兴奋性的产生。     

III类抗心律失常药RP58866对豚鼠及犬内向整流及瞬时外向钾电流的作用

目的：研究ＩＩＩ类抗心律失常药ＲＰ５８８６６ 对ＩＫ１ ,瞬时外向钾电流（Ｉｔｏ） 的作用。方法：用豚鼠和犬离体心肌细胞及全细胞电压钳技术。结果：在－ １００ ｍ Ｖ 时,ＲＰ５８８６６ 以浓度依赖方式明显减少了豚鼠心室肌细胞ＩＫ１ ,其ＩＣ５０ 为（３－４±０－８） μｍｏｌ·Ｌ－ １ 。在犬心室肌细胞,ＲＰ５８８６６ 可明显抑制Ｉｔｏ（ 在１００ μｍｏｌ·Ｌ－ １ 时减少８７％ ±２－１％ ）,其ＩＣ５０ 为（２－３±０－５） μｍｏｌ·Ｌ－ １ 。结论：ＲＰ５８８６６ 对心肌细胞的ＩＫ１ 和Ｉｔｏ 均有抑制作用,而不是一种特殊的ＩＫ１抑制剂     

Effects of recombinant humanen dothelial-derived interleukin-8 on hemorhagic shock in rats

目的：研究重组人内皮细胞衍生的白细胞介素－８（ＩＬ８）对失血性休克的作用．方法：大鼠股动脉放血至ＭＡＢＰ５３２ｋＰａ，维持９０ｍｉｎ，复制晚期失血性休克模型．输血后，静脉注射ＩＬ８２５０μｇ·ｋｇ－１．放免法测定血浆ＥＴ１和６ＫＰＧＦ１α含量．结果：给予ＩＬ８后，ＭＡＢＰ显著提高，休克状态改善，２ｈ存活率相应提高；休克晚期血浆ＥＴ１水平比正常明显升高（２１±４ｖｓ８２±１８ｎｇ·Ｌ－１，Ｐ＜００１），血浆６ＫＰＧＦ１α含量明显降低（１０７±１２ｖｓ１５７±１１ｎｇ·Ｌ－１，Ｐ＜００１）．ＩＬ８显著降低血浆ＥＴ１水平（１０±４ｎｇ·Ｌ－１，Ｐ＜００１），提高血浆６ＫＰＧＦ１α含量（３６８±１６ｎｇ·Ｌ－１，Ｐ＜００１）．结论：ＩＬ８具有较好的抗休克作用．     

No functional β_3-adrenergic receptors expressed in rat skeletal muscle cells

目的：研究原代培养的大鼠骨骼肌细胞中是否存在功能性β３肾上腺素受体（β３ＡＲ）．方法：利用柱层析方法测定异丙肾上腺素（Ｉｓｏ），β３ＡＲ激动剂ＣＧＰ１２１７７Ａ和β３ＡＲ拮抗剂ＳＲ５９２３０Ａ对培养骨骼肌细胞环磷腺苷（ｃＡＭＰ）生成作用．结果：Ｉｓｏ剂量依赖性刺激骨骼肌细胞ｃＡＭＰ的生成，ＥＣ５０为１５１ｎｍｏｌ·Ｌ－１．普萘洛尔０．１μｍｏｌ·Ｌ－１抑制Ｉｓｏ刺激的ｃＡＭＰ的生成，ＫＢ值为３４７ｎｍｏｌ·Ｌ－１．ＣＧＰ１２１７７Ａ无刺激ｃＡＭＰ生成作用，但可抑制Ｉｓｏ的作用．ＳＲ５９２３０Ａ１０ｎｍｏｌ·Ｌ－１不能抑制Ｉｓｏ刺激ｃＡＭＰ的产生．结论：大鼠骨骼肌细胞中不存在功能性β３ＡＲ或至少不与腺苷酸环化酶耦联     

2［对－（二甲氨基）苯乙烯］碘化甲基砒啶对豚鼠乳头肌慢反应动作电位和慢内向离子流的影响

用细胞内微电级和电压钳技术研究了２［对－（二甲氨基）苯乙烯］碘化甲基砒啶（ＤＳＰＭ）对豚鼠乳头肌慢反应动作电位（ＳＲＡＰ，）和慢内向电流（Ｉｓｉ）的影响。用ＤＳＰＭ液灌流５０分钟后，高Ｋ￣＋所致ＳＲＡＰ的振幅和零相最大上升速率均显著降低，Ｉｓｉ的峰值由８．８±１．６μＡ降至５．７±１．８μＡ。上述结果表明ＤＳＰＭ具有选择性阻断钙通道的作用     

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.

---

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.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

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.     

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.