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研究可乐定(Clo)对大鼠烫伤后心脏β肾上腺素受体(βAR)腺苷酸环化酶(AC)环腺苷一磷酸(cAMP)系统的作用.方法:大鼠于95℃水浴中烫9s,造成背部30%皮肤全层烫伤.用放射受体分析、间接方法、酶放射化学分析、放射免疫分析分别测定βAR密度和亲和力,AC和磷酸二酯酶(PDH)活性及cAMP生成量.结果:Clo(03、10和30mg·kg-1)增加烫伤后12h心肌βAR密度、AC活性及cAMP生成量(P<005或001);但Clo对烫伤大鼠心肌βAR亲和力、PDH活性及正常大鼠上述各项指标均无影响(P>005).育亨宾005mg·kg-1,部分逆转Clo对βAR密度、AC活性和cAMP生成的作用;哌唑嗪003mg·kg-1,对Clo的作用无明显影响.结论:Clo抑制烫伤后大鼠心肌βARACcAMP系统的变化. 相似文献
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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(β3AR).方法:利用柱层析方法测定异丙肾上腺素(Iso),β3AR激动剂CGP12177A和β3AR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151nmol·L-1.普萘洛尔0.1μmol·L-1抑制Iso刺激的cAMP的生成,KB值为347nmol·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β3AR或至少不与腺苷酸环化酶耦联 相似文献
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6-取代苯基-4,5-二氢-3(2H)-哒嗪酮衍生物的合成及其抑制血小板聚集活性 总被引:1,自引:1,他引:0
共合成了14个6取代苯基4,5二氢3(2H)哒嗪酮衍生物(Ⅱ1~14),除化合物(Ⅱ10)外均未见文献报道.对这些化合物及中间体(E1~3)进行了ADP诱导的家兔体外抑制血小板聚集实验,结果表明:(E1~3),(Ⅱ4),(Ⅱ9),(Ⅱ11)及(Ⅱ14)有较强的活性 相似文献
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运用“违法传递”概念,根据白念珠菌对寡肽的传送特点,设计并合成了8个含L4氧代赖氨酸(以下称I677)和N3(4甲氧基富马酰)L2,3二氨基丙酸(以下称FMDP)的寡肽类似物,均系新化合物。体外抗白念珠菌试验表明:I677FMDP肽(I677FMDP,I677AAFMDP,其中AA=Nva,Val,Leu,Phe,Pro,D,LpClPhe,DPgly)是I677单体摩尔活性的40~770倍,是FMDP的60~1130倍,其摩尔最低抑菌浓度为656×10-9~35×10-10mol·disk-1。羧肽酶A存在时化合物I677FMDP体外抗菌试验表明,含FMDP的化合物I677FMDP能抵抗羧肽酶A的酶解。 相似文献
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目的:研究抗虫灵对大鼠脑组织及肝脏某些生物转化酶的影响。方法:应用荧光分光光度法检测7乙氧基试卤灵O脱乙基酶(EROD)活性;以二硝基苯肼比色法测定B型单胺氧化酶(MAOB)活性;应用Habig法检测谷胱甘肽S转移酶(GST)活性。结果:体外实验中,抗虫灵对肝微粒体EROD活性有明显抑制作用,并能明显抑制脑线粒体MAOB活性,但对脑组织胞浆GST活性没有明显影响。整体实验中,抗虫灵能明显抑制肝微粒体和脑线粒体EROD活性,而且对多氯联苯诱导肝脏和脑组织EROD的效应有明显抑制作用;抗虫灵… 相似文献
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中药五味子中活性物质的化学研究-五味子醇甲的全合成 总被引:2,自引:0,他引:2
本文以没食子酸为原料进行还原偶合及脱水反应生成顺、反1,4二(3,4,5三甲氧基苯基)2,3二甲基2丁烯化合物(7)。将其进行硼氢化反应,然后分别与2,3二氯5,6二氰1,4苯醌(DDQ)和三氟醋酸铊(TTFA)在三氟醋酸(TFA)中进行非酚氧化偶合反应合成了中药五味子中活性化学成分五味子醇甲外消旋体,即(αRS)1,2,3,10,11,12六甲氧基6,7二甲基6羟基5,6,7,8四氢二苯骈[a,c]环辛烯(9)。元素分析,MS,UV,IR及NMR光谱数据均与天然五味子醇甲相符。 相似文献
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目的:研究抗孕唑(DL111IT)对离体大鼠黄体细胞孕酮合成和存活率的影响.方法:体外培养大鼠黄体细胞,用细胞计数和放射免疫法.结果:DL111IT使黄体细胞存活率随剂量上升而下降,ED50为77(71-85)mg·L-1.DL111IT3mg·L-1使黄体细胞基础黄体酮分泌下降25%,并可显著抑制弗司扣林(cAMP激动剂)10μmol·L-1和孕烯醇酮(可被3βHSD催化成黄体酮)10μmol·L-1的促孕酮分泌作用,抑制率分别为43%和155%,但不抑制hCG10IU·L-1的促黄体酮分泌作用.结论:DL111IT抗早孕作用是在cAMP和3βHSD水平上影响基础黄体酮分泌功能,并于高剂量降低黄体细胞成活率. 相似文献
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三种阿片受体激动剂对突触传递的抑制作用 总被引:1,自引:0,他引:1
袁孝如 《Acta pharmacologica Sinica》1996,(3)
目的:比较不同浓度三种阿片受体激动剂对突触传递的抑制作用.方法:用细胞内记录和细胞外微电泳技术,于大鼠伏核脑片制备上记录神经元的兴奋性突触后电位和谷氨酸钠所致细胞膜去极化.结果:(DAla2,NMePhe4,Glyol)enkephalin(DAGO),(DPen2,5)enkephalin(DPEN),andtrans(±)3,4dichloroNmethylN[2(1pyrolidinyl)cyclohexyl]benzeneacetamidemethanesulfonate(U50488H)(1μmol·L-1)均降低突触传递,尤以DAGO抑制作用最著.结论:三种阿片受体激动剂对突触传递的抑制作用均具有浓度依赖性,其作用机制与谷氨酸介导的突触传递受抑制有关. 相似文献
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目的:研究去甲肾上腺素(NE)介导大鼠肠系膜血管床(MVB)收缩的α1肾上腺素受体(α1AR)亚型.方法:用灌流大鼠MVB标本收缩功能实验和克隆细胞放射配体结合实验测定α1AR亚型选择性拮抗剂pA2和pKi,并作相关分析.结果:α1AAR选择性拮抗剂RS17053、WB4101、5MU及α1DAR选择性拮抗剂BMY7378的pA2分别为898±028,916±020,8.69±002和603±026,Schild作图斜率值与10差别无显著性.其pA2值与α1AAR的pKi相关系数为097,与α1B和α1DAR的相关系数分别为052和004.结论:介导外源性NE收缩大鼠MVB的功能性受体为α1AAR 相似文献
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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.相似文献
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Petrikovics I McGuinn WD Sylvester D Yuzapavik P Jiang J Way JL Papahadjopoulos D Hong K Yin R Cheng TC DeFrank JJ 《Drug delivery》2000,7(2):83-89
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. 相似文献
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《Critical reviews in toxicology》2013,43(5-6):327-369
AbstractThe 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. 相似文献
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Alberto García-Lled Javier Gmez-Pavn Juan Gonzlez del Castillo Teresa Hernndez-Sampelayo Mari Cruz Martín-Delgado Francisco Javier Martín Snchez Manuel Martínez-Sells Jos María Molero García Santiago Moreno Guilln Fernando Rodríguez-Artalejo Julin Ruiz-Galiana Rafael Cantn Pilar De Lucas Ramos Alejandra García-Botella Emilio Bouza 《Rev Esp Quimioter》2022,35(2):115
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. 相似文献
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《Expert opinion on investigational drugs》2013,22(1):79-86
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. 相似文献
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Chang Min Kim Kun Ho Son Sung Hwan Kim Hyun Pyo Kim 《Archives of pharmacal research》1991,14(4):305-310
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. 相似文献