内皮素-1受体拮抗剂的筛选和药理学研究

目的对军事医学科学院毒物药物研究所合成的系列内皮素受体拮抗剂进行筛选,并对有效化合物进行抗肺动脉高压的药理学研究。方法放射配体-受体结合实验测定受试化合物对ETA和ETB受体亚型的亲和力;在ET-1诱发离体大鼠主动脉环收缩、整体大鼠颈动脉压升高实验模型上进行生物活性筛选;在野百合碱诱发大鼠肺动脉高压实验模型上对受试化合物进行抗肺动脉高压的药效学研究。结果部分化合物与ETA受体的亲和力比与ETB受体的亲和力高万倍以上,并能有效地抑制ET-1诱发的离体大鼠主动脉环收缩,其中1μmol.L-1的受试化合物ETP-508可使ET-1累加浓度收缩效应曲线平行右移,且最大效应不变。此外,3.7μg.(0.5ml)-1.kg-1ET-1所致的大鼠体动脉压升高也可被2mg·kg-1ETP-508等化合物静脉注射所阻断;更进一步,ETP-508和BQ-485静脉给药(0.4mg.h-1)还可逆转80mg·kg-1野百合碱皮下一次注射诱发的大鼠肺动脉高压。结论以上结果提示,ETP-508和BQ-485是高选择性的ETA受体竞争性拮抗剂,能有效地抑制野百合碱诱发的大鼠肺动脉高压。     

盐酸埃他卡林对内皮素1诱导人离体肺动脉收缩的拮抗作用

目的 研究新型ATP敏感性钾通道(KATP)开放剂埃他卡林(IPT)对内皮素1(ET-1)诱导的人离体肺动脉收缩的影响及其机制.方法 建立ET-1诱导人离体肺动脉收缩的量效反应曲线和时效反应曲线,以吡那地尔(PIN)为阳性对照,研究IPT不同浓度累积给药的舒张血管效应.结果 在0.05～50 nmol/L浓度范围内,ET-1呈浓度依赖性地引起肺动脉收缩.其半数有效浓度±95%可信区间(EC50±L95)为(10.19±1.26) nmol/L,曲线斜率±标准差(b±sb)为0.905±0.186,相关系数r=0.91.在10-13～10-3 nmol/L浓度累积给药时,IPT呈浓度依赖性地拮抗ET-1诱导的肺动脉环收缩.其半数抑制浓度IC50为27.11 nmol/L.结论 IPT可以显著拮抗ET-1诱导的肺动脉收缩,其机制在于开放肺动脉平滑肌细胞上的KATP通道.IPT可以有效舒张人肺血管.     

新型ET_A受体选择性拮抗剂ETP-508衍生物抗肺动脉高压作用的药效学及毒性的筛选研究

目的该文对军事医学科学院毒物药物研究所合成的新型内皮素A(ETA)受体选择性拮抗剂ETP-508衍生物进行抗肺动脉高压的药效学及毒性的筛选研究,期望获得高效低毒的候选化合物。方法采用内皮素-1(ET-1)诱发离体大鼠主动脉环收缩、整体大鼠颈动脉压升高实验模型进行生物活性筛选;对活性较好的化合物进一步在慢性缺氧诱发大鼠肺动脉高压实验模型进行抗肺动脉高压的药效学评价;采用小鼠急性毒性试验及大鼠注射部位刺激性试验初步评价化合物的毒性。结果部分化合物(GF004、GF009、GF012、GF022、GF052、GF063、GF084)能有效抑制ET-1(10nmol·L-1)诱发的离体大鼠主动脉环收缩,其IC50值在10～100nmol·L-1水平;在整体水平上述化合物(2mg·kg-1,sc)抑制ET-1(3.7μg·kg-1)诱发的大鼠颈动脉压升高效应(P<0.05),抑制率为25%～45%,其中GF009和GF063抑制效应与ETP-508相当;在病理模型上,化合物GF009(25、50mg·kg-1,sc)和GF063(20、40mg·kg-1,sc)降低慢性缺氧诱发的大鼠肺动脉高压(P<0.05),抑制率分别为45.3%,59.9%和61.3%,73.7%,其效应与ETP-508相当。此外,GF009和GF063致小鼠急性毒性LD50值比ETP-508明显增加,皮下给药致大鼠注射部位刺激性明显减轻。结论以上结果提示,通过筛选获得的新型选择性ETA受体拮抗剂GF009和GF063不仅能有效地抑制慢性缺氧诱发的大鼠肺动脉高压,效果与ETP-508相当,而且毒性比ETP-508明显降低,值得进一步深入研究。     

埃他卡林对人肺动脉内皮细胞内皮素系统的作用

目的研究新型ATP敏感性钾通道(KATP)开放剂埃他卡林(iptakalim,IPT)对人肺动脉内皮细胞内皮素(ET)系统的作用。方法原代培养人肺动脉内皮细胞(HPAECs),分别加入不同浓度埃他卡林,共同孵育24h后;应用放射免疫法测定各组细胞上清内皮素-1(ET-1)浓度的变化,同时用逆转录多聚酶链反应(RT-PCR)方法检测各组细胞ET-1及内皮素转换酶(ECE)mRNA表达的变化。结果在IPT浓度为10-6mol·L-1及以上时,能够剂量依赖性地抑制HPAECs合成分泌ET-1,同时也降低ET-1mRNA的表达量;在IPT浓度为10-7mol·L-1及以上时,能够剂量依赖性地降低ECEmRNA的表达量。结论IPT通过抑制人肺动脉内皮细胞ET-1和ECEmRNA的表达量,继而抑制内皮细胞合成分泌ET-1,可能成为较有前途的治疗肺动脉高压的有效药物。     

盐酸丙哌维林对膀胱平滑肌收缩的影响(英文)

观察了盐酸丙哌维林 ( Pro)对离体豚鼠膀胱平滑肌自动节律性收缩和 KCl诱导离体豚鼠膀胱平滑肌收缩的影响 ;同时观察了 Pro对家犬在体膀胱自动节律性收缩的影响 .Pro在 1 ,1 0 μmol· L-1浓度时 ,对离体豚鼠膀胱平滑肌自动节律性活动具有兴奋作用 ,可使自动节律性收缩频率增加 ,幅度加大 ;在 1 0 0μmol· L-1浓度时则表现为抑制作用 ,可完全抑制豚鼠膀胱平滑肌的自动节律性收缩 ,同时可使平滑肌松弛 ,基础张力降低 .Pro对 KCl引起的豚鼠离体膀胱平滑肌的收缩具有明显的抑制作用 ,在 1 ,1 0 ,1 0 0 μmol· L-1浓度时对 KCl诱导豚鼠离体膀胱平滑肌收缩的抑制率分别为 ( 7.4±6.5) % ,( 31 .3± 1 2 .8) % ,( 68.4± 7.1 ) % ,其 IC50 为( 2 5.2± 4.7) μmol·L-1.十二指肠给 Pro对在体家犬膀胱自动节律性收缩具有明显的抑制作用 ,60 ,30mg· kg-1可明显降低膀胱自动节律性收缩频率和幅度且具有剂量依赖性 ,与药前比有显著性差异 ,60 mg· kg-1药后 1 0 min即可起效 ,药效可持续 90min,Pro在上述剂量下对血压 ,心率无明显影响 .本实验结果提示 Pro在低剂量时对离体膀胱自动节律性收缩具有一定的兴奋作用 ,在高剂量时则表现为明显的抑制作用 ;Pro对 KCl诱导的豚鼠离体膀胱平滑肌收缩和膀胱扩张诱导的家?     

注射用丹参总酚酸(冻干)对人CYP450酶和P-糖蛋白体外抑制作用及对大鼠CYP1A2和CYP3A体内诱导作用(英文)

目的探讨注射用丹参总酚酸(冻干)(SLI)对人CYP450酶和P-糖蛋白体外抑制作用以及对大鼠CYP1A2和CYP3A体内诱导作用。方法①应用P450-GloTMCYP450检测试剂盒,通过化学发光法测定SLI和经典抑制剂对细胞色素P4501A2(CYP1A2),CYP2D6,CYP3A4,CYP2C19和CYP2C9的IC50值,通过比较SLI和经典抑制剂对相应细胞色素P450亚型的IC50值来判断SLI对人CYP450酶的体外抑制作用。②Wistar大鼠分别iv给予SLI 3,10和30 mg·kg-1和诱导剂苯巴比妥钠20 mg·kg-1,采用探针底物法,通过比较代谢产物的生成速率来评价SLI对大鼠CYP1A2和CYP3A的诱导作用。③应用ATP酶检测试剂盒,通过化学发光法测定ATP酶活性来评价SLI是否为P-gp的底物或抑制剂。结果①CYP1A2,CYP2C9,CYP2C19,CYP2D6和CYP3A4抑制剂的IC50与SLI对其的IC50进行比较(CYP1A2:0.12μmol·L-1vs 840μmol·L-1;CYP2C9:3.362μmol·L-1vs 704μmol·L-1;CYP2C19:3.236μmol·L-1vs 306μmol·L-1;CYP2D6:0.117μmol·L-1vs 2660μmol·L-1;CYP3A4:0.078μmol·L-1vs 1780μmol·L-1)。②与空白对照组(86.4±6.3)nmol·g-1.min-1相比,SLI 3,10和30 mg·kg-1组CYP1A2活性分别为83.4±6.6,82.5±4.0和(83.4±6.6)nmol·g-1.min-1。与空白对照组(16.1±0.9)nmol·g-1.min-1比较,SLI 3,10和30 mg·kg-1组CYP3A活性分别为15.7±0.6,15.9±0.7和(15.9±1.0)nmol·g-1.min-1,无显著性差异。③以临床血药浓度为依据设计的一系列浓度的SLI 0.0002,0.0006,0.002,0.006,0.017,0.052,0.156和0.468 g.L-1的ATP酶活性分别与空白对照组进行比较(5.8,5.3,5.8,5.5,5.8,5.2,,5.8,5.3,vs 5.75μmol·g-1.min-1),无显著性差异。结论SLI临床给药剂量既不能体外抑制人CYP1A2,CYP2D6,CYP3A4,CYP2C19和CYP2C9酶活性,也不能诱导大鼠CYP1A2和CYP3A,同时也不是P-gp的体外抑制剂或底物。     

次黄嘌呤与氧嗪酸钾不同剂量配伍制备高尿酸血症大鼠模型

目的确定次黄嘌呤与尿酸酶抑制剂氧嗪酸钾(OAPS)伍用制备高尿酸血症大鼠模型的合适剂量,为制备持续性高尿酸血症及痛风大鼠模型提供实验依据。方法给大鼠不同配伍剂量的次黄嘌呤(ig)与OAPS(sc)制备代谢性高尿酸血症大鼠模型,于造模后不同时间观察模型大鼠血清尿酸、尿素氮和肌酐水平。结果次黄嘌呤分别为125,250和500mg·kg-1,OAPS以25,50和100mg·kg-1与每个剂量的次黄嘌呤伍用造模。造模后3h血清尿酸和肌酐浓度均有所升高,造模后9h血清尿素氮浓度明显升高。在次黄嘌呤为500mg·kg-1,OAPS为100mg·kg-1时,造模后3,9和12h模型大鼠血清尿酸浓度分别为(781±167),(627±291)和(366±196)μmol·L-1,明显高于正常对照组(86±10),(75±16)和(80±15)μmol·L-1;造模后24h,血清尿素氮和肌酐水平〔(199±96)mg.L-1和(55±16)μmol·L-1〕均明显高于正常对照组〔(61±5)mg.L-1和(21±2)μmol·L-1〕。结论次黄嘌呤500mg·kg-1和OAPS100mg·kg-1伍用制备的代谢性高尿酸血症大鼠模型具有血清尿酸浓度高和维持时间长的特点。     

埃他卡林对慢性低氧性肺动脉高压大鼠肺组织HIF-1α mRNA和蛋白表达的影响

目的 研究新型ATP敏感性钾通道开放剂(KATP CO)埃他卡林(IPT)对大鼠肺组织中低氧诱导凶子1α(HIF-1α)表达的影响.方法 36只清洁级SD大鼠随机分成对照组、低氧性肺动脉高压(HPH)模型组和IPT处理组,每组12只.HPH模型组及IPT处理组于(10.0±0.5)%氧浓度的常压低氧舱内饲养,每天8 h,每周6 d,共4周.IPT处理组给予IPT 1.5 mg·kg-1·d-1灌胃;对照组及HPH模型组给予0.9%氯化钠5 ml·kg-1·d-1灌胃.用逆转录聚合酶链反应(RT-PCR)方法检测肺组织HIF-1α mRNA表达,用Western blot方法检测肺组织HIF-1α白的表达.结果 HPH模型组大鼠肺动脉平均压、右室/(左室+室间隔)重量比和HIF-1α mRNA和蛋白表达均高于对照组和IPT处理组(P＜0.01).IPT处理组与对照组的HIF-1α mRNA和蛋白表达差异无统计学意义(P＞0.05).结论 IPT降低肺动脉压可能与抑制HPH大鼠肺组织中的HIT-1α表达有关.     

姜黄素在大鼠体内药代动力学和生物利用度研究

目的研究姜黄素不同给药途径在大鼠体内的药代动力学和绝对生物利用度。方法建立大鼠血浆中姜黄素的HPLC检测方法。考察大鼠分别经灌胃ig(200 mg·kg-1)、ip腹腔注射(20 mg·kg-1)、舌下静脉iv(10 mg·kg-1)给予姜黄素后血药浓度变化。用DAS2.0软件计算药动学参数,根据腹腔注射、灌胃和静脉给药药-时曲线下面积AUC(0-∞)和给药剂量,计算腹腔注射和口服姜黄素的绝对生物利用度。结果姜黄素浓度在0.05～6.00 mg·L-1范围内线性关系良好(r=0.9998);定量下限为0.05 mg·L-1;低(0.10 mg·L-1)、中(1.00 mg·L-1)、高(4.00 mg·L-1)3个浓度的回收率分别为(99.29±5.40)%、(104.21±4.72)%和(99.83±1.97)%;日内RSD分别为4.49%、3.90%和1.72%,日间RSD分别为4.61%、4.27%和2.00%。大鼠经灌胃、腹腔注射和静脉注射姜黄素后,姜黄素在大鼠体内的代谢过程均符合二室模型,消除半衰期分别为(159.28±18.12)、(90.79±11.55)和(11.96±2.64)min;AUC(0-∞)分别为(86.36±12.90)、(73.39±8.72)、(104.62±11.89)mg.min.L-1。按剂量折算,姜黄素经腹腔注射给药的绝对生物利用度为35.07%,灌胃给药的绝对生物利用度为4.13%。结论姜黄素经不同途径给药在大鼠体内的药代动力学过程相似,腹腔注射给药的绝对生物利用度较高,口服生物利用度低。     

腺苷对慢性低氧高二氧化碳大鼠肺动脉高压的影响

目的　观察腺苷对慢性低氧高二氧化碳大鼠血流动力学的影响及氨茶碱的拮抗作用。方法　从大鼠肺动脉内注入腺苷溶液。氨茶碱组大鼠预先注入氨茶碱进行处理。结果　 2 5 μg·kg-1·min-1组 (T组 ) ,5 0 μg·kg-1·min-1组 (F组) ,10 0 μg·kg-1·min-1组 (H组 )用药后平均肺动脉压(mPAP)分别降低 18 5 %± 9 9% ,2 7 1%± 4 5 % ,37 2 %± 7 2 % ,明显低于用药前 (P均 <0 0 1) ,而NO水平则明显升高 (P <0 0 5 ,P <0 0 1,P <0 0 1)。T组 ,F组用药后mPAP/mSAP(平均体循环压 )明显低于用药前 (P <0 0 1,P<0 0 5 ) ,H组差异无显著性 (P >0 0 5 )。氨茶碱组用药后mPAP与F组比较差异有显著性 (P <0 0 1)。结论　腺苷剂量依赖性降低慢性低氧高二氧化碳大鼠的肺动脉高压 ,其机制可能部分依赖于内皮细胞NO的释放。小剂量腺苷对肺循环具有良好选择性。氨茶碱能拮抗腺苷舒张肺血管的作用。     

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.

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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.