莲心碱对大鼠缺血再灌注损伤心肌的保护作用

目的:研究莲心碱对大鼠缺血再灌注损伤心肌的保护作用.方法:实验大鼠24只,随机分为3组,每组8只.假手术组:冠状动脉左前降支(LAD)处穿一丝线,但不结扎;损伤对照组:结扎冠状动脉LAD,造成心肌缺血再灌注损伤;药物组:结扎冠状动脉LAD前静脉注射莲心碱5 mg•kg 1.测定每组大鼠血清中磷酸肌酸激酶(CPK)、乳酸脱氢酶(LDH)活性,丙二醛(MDA)含量,心肌梗死范围(IS).结果:与假手术组和损伤对照组比较,药物组血清CPK、LDH活性与MDA含量明显降低(P＜0.01),心肌梗死面积减少(P＜0.05).结论:莲心碱对大鼠缺血再灌注损伤心肌有保护作用.     

血栓通预处理对大鼠心肌缺血再灌注损伤的影响

目的:研究血栓通对大鼠缺血心肌的保护作用。方法:选用40只Wister大鼠分为正常对照组、模型组、血栓通组及维拉帕米组,采用结扎大鼠冠状动脉左前降支建立出大鼠心肌缺血再灌注损伤模型。检测大鼠血清磷酸肌酸激酶(CPK)、乳酸脱氢酶(LDH)、血清及心肌组织超氧化物歧化酶(SOD)和脂质过氧化物丙二醛(MDA),研究血栓通对心肌梗死范围的影响。结果:血栓通可对抗结扎大鼠冠状动脉左前降支所致的大鼠急性心肌损伤,使心肌缺血大鼠的CPK及LDH降低,并可增加心肌组织SOD的活性,减少MDA生成且能显著缩小心肌梗死的范围。结论:血栓通对大鼠心肌缺血有保护作用,其机制可能与抗脂质过氧化反应有关。     

淡竹叶黄酮对大鼠心肌缺血/再灌注损伤的保护作用

目的研究淡竹叶总黄酮(TFLG)对大鼠心肌缺血/再灌注损伤的作用及其机制。方法采用结扎大鼠左冠状动脉前降支法,建立心肌缺血/再灌注损伤模型。测定血清乳酸脱氢酶(LDH)、肌酸激酶(CK)、超氧化物歧化酶(SOD)、丙二醛(MDA)、谷胱甘肽过氧化物酶(GSH-PX)、一氧化氮(NO)含量。结果 TFLG 50、100 mg.kg-1可抑制大鼠心肌中LDH及CK的漏出,降低血清和心肌组织中LDH与CK活性,降低MDA含量,提高SOD、GSH-PX和NO浓度。TFLG 100 mg.kg-1可抑制NF-κB和TNF-α蛋白的表达,下调caspase-3蛋白表达。结论 TFLG对心肌缺血/再灌注损伤有一定的保护作用,其作用机制可能与抗自由基、抑制炎症反应和减少细胞凋亡有关。     

甘草酸二铵对大鼠心肌缺血再灌注损伤脂质过氧化及心肌酶活性的影响

目的:观察甘草酸二铵(DG)对大鼠心肌缺血再灌注损伤脂质过氧化及心肌酶活性的影响。方法:雄性wistar大鼠30只,随机分为假手术组、缺血再灌注组和DG20mg·kg-1组。每组10只。采用在体大鼠心肌缺血30min再灌注60min损伤模型,再灌注60min后分别用比色法测定心肌丙二醛(MDA)含量、超氧化物歧化酶(SOD)、三磷酸腺苷酶(ATP酶)、血清磷酸肌酸激酶(CPK)和乳酸脱氢酶(LDH)水平,并用酶组织化学方法检测心肌组织琥珀酸脱氢酶(SDH)的活性。结果:DG能显著降低心肌组织中MDA含量和SDH的活性(P<0.05,P<0.01),提高SOD和ATP酶活性(P<0.05,P<0.01),并减少心肌CPK和LDH的释放(P<0.05,P<0.01)。结论:DG具有保护大鼠心肌缺血再灌注损伤的作用,其作用机理可能与其降低心肌脂质过氧化,增强心肌细胞SOD、SDH和ATP酶活性有关。     

保心康对异丙肾上腺素致大鼠心肌缺血的保护作用

目的观察保心康（BXK）对异丙肾上腺素（ISO）所致大鼠急性心肌缺血的保护作用。方法采用改良的Rona法复制大鼠急性心肌缺血模型,检测大鼠心电图（ECG）改变及血清中超氧化物歧化酶（SOD）活性、丙二醛（MDA）、乳酸（LD）、乳酸脱氢酶（LDH）以及肌酸磷酸激酶（CPK）含量,测定心肌含水量以及观察心肌组织病理改变。结果与心肌缺血模型组比较,BXK（18、36 mg·kg^-1）可显著改善心肌缺血大鼠心电图S-T段抬高,明显提高心肌缺血大鼠血清中SOD活性,降低MDA含量,降低LD,LDH和CPK含量。BXK（18、36 mg·kg^-1）能够不同程度减少心肌含水量及心肌缺血大鼠心肌组织病理损伤。结论保心康对大鼠急性心肌缺血模型具有明显的保护作用。     

1,6-二磷酸果糖镁对异丙肾上腺素所致大鼠心肌损伤的保护作用

研究 1 ,6-二磷酸果糖镁 ( FDP- Mg)对异丙肾上腺素 ( Iso)所致心肌损伤的保护作用 .大鼠 sc Iso( 8mg· kg-1· d-1,3d)造成心肌损伤模型 ,测定心肌组织和血清肌酸激酶 ( CK) ,乳酸脱氢酶( LDH) ,超氧化物歧化酶 ( SOD)活性及丙二醛( MDA) ,Mg2 ,P和 K 含量 .结果 :每天给予 Iso的同时给予 FDP- Mg( 2 50 - 1 0 0 0 mg· kg-1· d-1,3d)能明显降低血清 CK,LDH水平 ,抑制心肌组织中 CK,LDH释放 ,提高血清和心肌 SOD活性 ,降低MDA水平 ,提高心肌及血清 Mg2 和 P含量 ,降低血清 K 浓度。综合了 FDP- Na2 ( 530 mg· kg-1·d-1,3d)和硫酸镁 ( 1 50 mg· kg-1· d-1,3d)的作用特点。结果表明 ,FDP- Mg对 Iso所致大鼠心肌损伤具有保护作用 ,与其抗氧化及改善心肌代谢有关 .     

玉郎伞提取物对大鼠心肌缺血再灌注损伤的保护作用

目的:研究玉郎伞(YLS)对心肌缺血再灌注损伤(MIRI)的影响.方法:以Wistar大鼠制备MIRI模型(结扎冠状动脉5 min后再灌注30 min),观察YLS对心肌梗死面积及心肌组织丙二醛(MDA)含量、超氧化物歧化酶(SOD)活力及血清中乳酸脱氢酶(LDH)、肌酸磷酸激酶(CK)活性生化指标的影响.结果:YLS明显降低心肌梗死范围、提高心肌组织中SOD活力、降低其MDA含量,同时降低血清中CK和LDH活力(P<0.01或P<0.05).结论:YLS对大鼠心肌缺血再灌注损伤具有显著的保护作用.     

3,6-(二甲氨基)-二苯并碘杂六环葡萄糖酸盐对大鼠心肌缺血再灌注损伤保护作用机制初步探讨

目的:探讨3,6-(二甲氨基)-二苯并碘杂六环葡萄糖酸盐(IHC-93)对心肌缺血再灌注保护作用的机制.方法:选用SD健康大鼠,结扎和松解冠状动脉制备心肌缺血再灌注模型.结果:IHC-93在0.125,0.25和0.5 mg·kg-1剂量下能明显增加心肌超氧化物歧化酶(SOD)活性,减少血清和心肌丙二醛(MDA)含量;显著增加血清6-酮前列腺素F1α(6-Keto-PGF1α)含量及显著降低血栓素B2(TXB2)含量.结论:IHC-93对大鼠心肌缺血再灌注损伤的保护作用机制可能与抗脂质过氧化反应,增加PGI2和降低TXB2含量有关.     

11-羰基-β-乙酰乳香酸对盐酸异丙肾上腺素诱导大鼠心肌缺血的保护作用

目的:研究11-羰基-β-乙酰乳香酸(AKBA)对盐酸异丙肾上腺素(ISO)诱导大鼠心肌缺血损伤的保护作用机制。方法:SD大鼠随机分为空白组、模型组、AKBA低剂量组、AKBA高剂量组。皮下注射ISO 100 mg·kg-1诱导心肌缺血损伤模型后,测定各组大鼠心电图ST段变化,检测血清的肌酸激酶同工酶(CK-MB)、心肌钙蛋白I(c Tn I)、乳酸脱氢酶(LDH)、丙二醛(MDA)、超氧化物歧化酶(SOD)的含量变化,观察心肌组织病理性改变,检测心肌细胞的凋亡情况。结果:AKBA高剂量组大鼠心电图ST段移位显著低于模型组;AKBA高剂量组能显著降低大鼠血清中心肌酶的CK-MB、c Tn I、LDH;AKBA高剂量组降低大鼠血清中MDA,升高SOD活力;AKBA高剂量组的心肌组织病理损伤小于模型组;AKBA高剂量组抑制心肌缺血损伤中的心肌细胞的凋亡。结论:AKBA组能有效抑制ISO所致心肌缺血损伤,抑制心肌细胞凋亡,对心肌具有保护作用。     

龙血竭总黄酮对动物心肌缺血的保护作用

目的:观察龙血竭总黄酮对大鼠、犬急性心肌缺血的保护作用。方法:股静脉注射垂体后叶素致大鼠急性心肌缺血,观察心电图变化;结扎麻醉犬冠状动脉致心肌缺血,测定缺血范围、心外膜电图及血清CK、LDH、LD浓度。结果:与模型对照组相比,360、180mg·kg-1龙血竭总黄酮灌胃给药能对抗垂体后叶素所致大鼠心肌缺血心电图J点、T波的变化;120、60、30mg·kg-1龙血竭总黄酮十二指肠给药能缩小冠状动脉结扎所致犬心肌缺血梗死范围,降低心电图的ST段比结扎前抬高≥2mv以上的个数(△NST)和心电图的ST段于结扎前抬高的差值(△ΣST);减少血清中CK、LDH、LD释放。结论:龙血竭总黄酮对大鼠、犬急性心肌缺血有较好的保护作用。     

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.     

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.     

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.