硝普钠与异丙肾上腺素松弛犬气管平滑肌的协同作用

目的：研究硝普钠（ＳＮＰ）与异丙肾上腺素（ＩＳＯ）对犬气管平滑肌松弛作用是否存在协同关系，并分析协同的机制。方法：采用放射免疫分析法测定犬气管平滑肌环核苷酸量，并用磷酸二酯酶（ＰＤＥ）同工酶抑制剂为工具分析ＳＮＰ与ＩＳＯ相互作用的机制。结果：ＳＮＰ（１～１００μｍｏｌ·Ｌ－１）增强ＩＳＯ（３０μｍｏｌ·Ｌ－１）对３μｍｏｌ·Ｌ－１乙酰甲胆碱预收缩的犬气管平滑肌的松弛作用。ＳＮＰ（１００μｍｏｌ·Ｌ－１）与ＩＳＯ（３０μｍｏｌ·Ｌ－１）对犬气管平滑肌松弛的协同作用伴有气管平滑肌中ｃＡＭＰ积聚比ＳＮＰ与ＩＳＯ单独时分别增加１．２倍与０．４倍。ＰＤＥⅤ抑制剂扎普司特（３μｍｏｌ·Ｌ－１）使ＳＮＰ的气管平滑肌ｃＧＭＰ积聚由２．４倍增加到４．６倍，可进一步增加气管松弛作用１．２倍。合并ＰＤＥⅢ抑制剂氰胍哒嗪（３０μｍｏｌ·Ｌ－１）和ＰＤＥⅣ抑制剂咯利普兰（３０μｍｏｌ·Ｌ－１）或合并ＳＮＰ（１００μｍｏｌ·Ｌ－１）和咯利普兰（３０μｍｏｌ·Ｌ－１）均能进一步增强ＩＳＯ的气管ｃＡＭＰ积聚与松弛作用。结论：ＳＮＰ是通过气管平滑肌ｃＧＭＰ含量增加而抑制ＰＤＥⅢ，导致ＳＮＰ与ＩＳＯ对气管松弛的协同作用。     

咯利普兰逆转豚鼠离体气管对沙丁胺醇的耐受性

本研究目的旨在观察ＰＤＥＩＶ抑制剂咯利普兰对沙丁胺醇（ＳＢ）耐受性的影响。用豚鼠离体气管标本，预先接触ＳＢ１μｍｏｌ·Ｌ－１，１ｈ可使ＳＢ对抗乙酰甲胆碱气管收缩作用的剂量反应曲线右移５倍，最大松弛率下降３０％，形成ＳＢ气管松弛作用的耐受性。磷酸二酯酶（ＰＤＥ）ＩＶ抑制剂咯利普兰能翻转ＳＢ气管松弛作用的耐受性，但ＰＤＥＩＩ抑制剂氰胍哒嗪则不能。虽然蛋白合成抑制剂环己酰亚胺对ＳＢ耐受性无预防作用，但上述结果仍提示ＳＢ气管松弛作用的耐受性可能与ＰＤＥＩＶ活性的增高有关。     

磷酸二酯酶同工酶Ⅲ和Ⅳ调节气管平滑肌环腺苷酸的区域化分布

磷酸二酯酶同工酶Ⅳ（ＰＤＥⅣ）抑制剂咯利普兰（Ｒｏｌ，３０μｍｏｌ·Ｌ－１）对３０μｍｏｌ·Ｌ－１异丙肾上腺素所致的犬气管平滑肌环腺苷酸（ｃＡＭＰ）积聚的增强作用比ＰＤＥⅢ抑制剂氰胍哒嗪（ＳＫＦ９４８３６，３０μｍｏｌ·Ｌ－１）要强，但对异丙肾上腺素所致的犬气管平滑肌松弛的增强作用比ＳＫＦ９４８３６要弱．３０μｍｏｌ·Ｌ－１Ｒｏｌ或ＳＫＦ９４８３６对３０μｍｏｌ·Ｌ－１福斯科林所致的犬气管平滑肌松弛与ｃＡＭＰ积聚的增强作用程度几乎相等．异丙肾上腺素，福斯科林单独或与ＳＫＦ９４８３６，Ｒｏｌ合用都仅引起犬气管平滑肌的可溶部ｃＡＭＰ积聚，对颗粒部ｃＡＭＰ含量无明显影响．上述结果提示犬气管平滑肌存在着ｃＡＭＰ的区域化分布，它受ＰＤＥⅢ，ＰＤＥⅣ的调节，而与平滑肌细胞的亚细胞结构无关     

磷酸二酯酶同工酶Ⅲ和Ⅳ调节气管平滑肌环腺鞋酸的区…

磷酸二酯酶同工酶Ⅳ（ＰＤＥⅣ）抑制剂咯利普兰（Ｒｏｌ，３０μｍｏｌ·Ｌ＾－１）对３０μｍｏｌ·Ｌ＾－１异丙肾上腺素所致的犬气管平滑肌环腺苷酸（ｃＡＭＰ）积聚的增强作用比ＰＤＥⅢ抑制剂氰腺哒嗪（ＳＫＦ９４８３６，３０μｍｏｌ·Ｌ－１）要强，但对异丙肾上腺素所致的犬气管平滑肌松弛的增强作用比ＳＫＦ９４８３６要弱。３０μｍｏｌ·Ｌ＾－１Ｒｏｌ或ＳＫＦ９４８３６对３０μｍｏｌ·Ｌ＾－１福斯科林所致的犬气管     

盐酸二氢埃托啡对奥狄氏括约肌收缩和放电活动的影响

观察了盐酸二氢埃托啡（ＤＨＥ）对豚鼠和兔离体和在体奥狄氏括约肌运动的作用．结果发现，ＤＨＥ１．０－１００μｍｏｌ·Ｌ－１可浓度依赖性地舒张豚鼠离体和在体奥狄氏括约肌；ＤＨＥ５μｇ·ｋｇ－１ｉｖ抑制兔在体奥狄氏括约肌放电．在相同条件下，吗啡０．１－１００μｍｏｌ·Ｌ－１能浓度依赖性地诱发豚鼠离体和在体奥狄氏括约肌收缩；吗啡５ｍｇ·ｋｇ－１ｉｖ增加兔在体奥狄氏括约肌放电．结果提示ＤＨＥ和吗啡对奥狄氏括约肌的作用性质完全相反，前者抑制，后者兴奋．     

蝙蝠葛碱对心肌去甲肾上腺腺出胞释放的影响

目的 研究蝙蝠葛碱对心肌去甲肾上腺素（ＮＥ）出胞释放的药理作用，方法 用高压液相色谱－电化学法测定电刺激时豚鼠离体灌注心脏流出液的ＮＥ含量，结果 不加实验条件时第１次电刺激（Ｓ１）与第２次电刺激（Ｓ２）所引起的ＮＥ释放量无差别（Ｐ〉０．０５），蝙蝠葛碱（３０μｍｏｌ．Ｌ＾－１）维持帕米（５μｍｏｌ．Ｌ＾－１）明显减少Ｓ２引起的ＮＥ释放（Ｐ〈０．０１，Ｐ〈０．０５），组间比较，蝙蝠葛碱组，维拉帕米组     

阿片类药物在豚鼠离体回肠中的交互依赖性和交互耐受性

研究了阿片类药物在豚鼠离体回肠中的交互依赖性和交互耐受性．豚鼠回肠分别与羟甲芬太尼（ＯＭＦ１ｎｍｏｌ·Ｌ－１），Ｄ－Ａｌａ２，Ｄ－Ｌｅｕ５－脑啡肽（ＤＡＤＬＥ，０．３μｍｏｌ·Ｌ－１）或Ｕ５０４８８Ｈ（５０ｎｍｏｌ·Ｌ－１）在３７℃温育４ｈ，它们相互及自身均能抑制纳洛酮（０．１μｍｏｌ·Ｌ－１）或Ｍｒ２２６６（０．１μｍｏｌ·Ｌ－１）引起的戒断性收缩．它们也能自身预先阻断戒断性收缩的产生．Ｕ５０４８８Ｈ能预先阻断ＯＭＦ，ＤＡＤＬＥ温育后纳洛酮所产生的戒断性收缩，但后两者不能预先阻断Ｕ５０４８８Ｈ温育后由Ｍｒ２２６６所产生的戒断性收缩，并且ＯＭＦ和ＤＡＤＬＥ之间也不能相互阻断．豚鼠回肠分别与ＯＭＦ（１ｎｍｏｌ·Ｌ－１），ＤＡＤＬＥ（０．３μｍｏｌ·Ｌ－１）在３７℃温育２ｈ后，对去甲吗啡（ＮＭ），ＯＭＦ，ＤＡＤＬＥ的敏感性明显下降，浓度反应曲线右移，但对Ｕ５０４８８Ｈ不产生耐受．在Ｕ５０４８８Ｈ（１０ｎｍｏｌ·Ｌ－１）中温育１ｈ的回肠，对Ｕ５０４８８Ｈ的敏感性下降，浓度反应曲线右移，但对ＯＭＦ，ＮＭ，ＤＡＤＬＥ的敏感性不变．这些结果表明豚鼠回肠中μ，κ阿片受体是分离的．     

速激肽受体拮抗剂对豚鼠组胺反应的影响

目的：探讨速激肽与组胺（Ｈｉｓ）反应的关系。方法：观察速激肽受体拮抗剂对豚鼠Ｈｉｓ的整体和离体的呼吸道和心血管效应。结果：单用或合用速激肽ＮＫ－１受体拮抗剂ＣＰ－９６３４５（１ｍｇ·ｋｇ－１，ｉｐ）及ＮＫ－２受体拮抗剂ＳＲ－４８９６８（１ｍｇ·ｋｇ－１，ｉｐ）均可显著降低清醒豚鼠吸入Ｈｉｓ气雾的气道反应性。ＣＰ－９６３４５（１ｍｇ·ｋｇ－１，ｉｖ）可显著降低静脉注射Ｈｉｓ引起麻醉豚鼠支气管和心房的伊文思蓝渗出，ＳＲ－４８９６８（１ｍｇ·ｋｇ－１，ｉｖ）则对肺内压升高有较弱的抑制作用，两药对平均动脉压降低无明显作用。在豚鼠的离体气管和支气管平滑肌标本，ＣＰ－９６３４５（１μｍｏｌ·Ｌ－１）及ＳＲ－４８９６８（１μｍｏｌ·Ｌ－１）对Ｈｉｓ的Ｅｍａｘ及ｐＤ２无明显作用。结论：速激肽部分参与了豚鼠的Ｈｉｓ炎症反应，速激肽受体拮抗剂有抗炎作用。     

淫羊藿总黄酮对肾上腺素能受体阻断作用的研究

淫羊藿总黄酮（ＴＦＥ，０，１３ｇ·Ｌ－１）抑制兔离体右心房肌的肌力和心率，此作用无Ｍ受体激动效应和钙拮抗作用，能使异丙肾上腺素（ＩＳＯ，１０－７ｍｏｌ·Ｌ－１）对心房肌的正性频率作用的量效曲线平行右移。ＴＦＥ不影响ＩＳＯ（１０－７ｍｏｌ·Ｌ－１）对豚鼠气管条的负性肌力作用和去甲肾上腺素（ＮＥ，１０－６ｍｏｌ·Ｌ－１）对兔主动脉条的正性肌力作用。ＴＦＥ（ｉｖ，１００ｍｇ·ｋｇ－１）明显降低麻醉猫和大鼠血压，减弱ＩＳＯ（１０μｇ·ｋｇ－１）所致的大鼠心率加快的作用，但对ＩＳＯ和肾上腺素（Ａｄｒ）的降压作用无影响，也不增敏Ａｄｒ的升压作用。实验结果证实ＴＦＥ选择性阻断离体及整体动物心肌β１受体，对气管β２受体和血管平滑肌α受体无阻断作用。     

O-(4-乙氧基丁基)小檗胺对离体蛙心的影响

目的：探讨Ｏ（４乙氧基丁基）小檗胺（ＥＢＢ）对离体蛙心的影响．方法：应用Ｓｔｒａｕｂ法制备离体蛙心；使用ＬＭＳ２Ａ记录仪经张力换能器描记心脏活动．结果：ＥＢＢ１－１００μｍｏｌ·Ｌ－１剂量依赖性增强蛙心收缩与舒张活动，但不影响心率；ＥＢＢ２５０－５００μｍｏｌ·Ｌ－１则引起心跳减慢，甚至停搏．ＥＢＢ的正性肌力作用不受西咪替丁１０μｍｏｌ·Ｌ－１和哌唑嗪１００μｍｏｌ·Ｌ－１影响；但可被维拉帕米０．０１μｍｏｌ·Ｌ－１所拮抗．ＥＢＢ能增强ＣａＣｌ２的正性肌力作用．与咖啡因和异丙肾上腺素比较，ＥＢＢ起效较慢，作用持续时间较长；但室温为（２１．０±０．５）℃时，与哇巴因比较却恰好相反．结论：ＥＢＢ的正性肌力作用至少部分是通过促进外Ｃａ２＋内流而非促进内Ｃａ２＋释放所致．     

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.     

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.