大黄酸联合吡格列酮对大鼠非酒精性脂肪性肝炎治疗作用机制的探讨

目的探讨大黄酸联合吡格列酮对高脂诱建的大鼠NASH协同治疗及其可能的作用机制。方法清洁级SD大鼠140~160 g,♂,76只正常喂养1周后,随机分成6组(对照组、模型组各为14只,余组均为12只):对照组,模型组,大黄酸组,吡格列酮组,大黄酸吡格列酮联合低剂量组,高剂量组。模型组高脂高胆固醇饲料由普通饲料+10%猪油+2%胆固醇配制,药物组均在12周高脂饮食后即造模成功后给予干预。大黄酸用生理盐水配成5 g.L 1混悬液,每天固定时间100 mg.kg 1.d 1灌胃,吡格列酮组8 mg.kg 1.d 1,联合低剂量组取其相对有效低剂量,大黄酸50 mg.kg 1.d 1,吡格列酮组4 mg.kg 1.d 1。联合高剂量组为大黄酸100 mg.kg 1.d 1,吡格列酮组8 mg.kg 1.d 1。于第20周处死。所有动物测体重、肝湿重,计算肝指数;测空腹血糖、转氨酶及血脂水平,放免法测空腹胰岛素及TNF-,计算胰岛素抵抗指数;酶法测定肝组织匀浆MDA、GSH-PX水平;HE染色肝病理组织切片。结果第20周模型组大鼠血糖、胰岛素、血脂、ALT、AST及胰岛素抵抗指数较对照组明显增高;肝组织出现重度脂肪变性,均出现小叶内炎症细胞浸润和散在的灶性坏死;药物组大鼠的生化指标和脂肪变及炎症程度较模型组均有明显减轻,联合组较药物单用组更为有效。结论大黄酸联合吡格列酮较两药单用能更有效抑制脂质过氧化反应及改善胰岛素抵抗,对大鼠NASH具有明显的协同治疗作用。     

大黄酸和吡格列酮对实验性大鼠非酒精性脂肪性肝炎治疗作用的比较

目的：探讨大黄酸和吡格列酮各自对高脂诱建的大鼠非酒精性脂肪性肝炎（NASH）的影响及其可能的机制。方法：52只清洁级雄性SD大鼠,体重140～160g,随机分成4组：对照组（n=14）、模型组（n=14）、大黄酸组（n=12）、吡格列酮组（n=12）。模型组由高脂高胆固醇饲料（普通饲料＋10％猪油＋2％胆固醇配制）喂养,药物组均在12周高脂饮食后即造模成功后给予干预。大黄酸用生理盐水配成5g／L混悬液,每天固定时间100mg·kg^-1·d^-1灌胃,吡格列酮组8mg·kg^-1·d^-1灌胃。于第20周处死。测定所有动物体重、肝湿重、计算肝指数;测定空腹血糖（FBG）、转氨酶及血脂水平;放射免疫法测空腹胰岛素（FINS）及TNF—α,计算胰岛素抵抗指数;酶法测定肝组织匀浆丙二醛（MDA）、谷胱甘肽过氧物酶（GSH-Px）水平;HE染色肝病理组织切片。结果：与模型组相比,药物组AⅡ、AST、血糖、胰岛素及胰岛素抵抗指数、TNF-α MDA有明显下降;大黄酸组肝脂肪变较吡格列酮组明显（P〈0．05）,但其肝内炎症较吡格列酮组轻。结论：大黄酸和吡格列酮对大鼠NASH均有治疗作用,但在改善肝脂肪变及炎症方面有所不同。     

吡格列酮改善高脂饮食导致的大鼠肝脏胰岛素抵抗

目的：观察大鼠肝脏中氧化应激以及胰岛素抵抗的发生并探讨吡咯列酮对高脂饮食导致的大鼠肝脏胰岛素抵抗的改善作用。方法：取4周龄雄性SD大鼠,实验分为4组：对照组,高脂组,吡咯列酮组、吡咯列酮＋高脂组。喂养12周后,称体重后断尾法留取空腹血标本,取血测定空腹血糖浓度、血清胰岛素,并计算胰岛素敏感指数;糖原检测试剂盒检测肝脏组织中糖原含量;DHE染色观察肝脏组织中的活性氧自由基水平。结果：正常大鼠的胰岛素敏感指数为-3.47±0.39,高脂饲料喂养12周后,大鼠空腹血糖水平上升,而胰岛素敏感指数降低为-6.29±0.54,吡咯列酮能降低血糖,增加胰岛素敏感指数为-4.54±0.33。蒽酮法的检测结果显示高脂饲料喂养大鼠肝组织糖原含量显著降低到（13.6±2.7）mg/g,吡咯列酮能促进肝脏糖原合成[（19.62±2.88）mg/g]。DHE染色显示肝组织活性氧自由基水平显著增加,吡咯列酮能降低氧化应激水平。结论：高脂饲料喂养SD大鼠胰岛素敏感指数降低,肝组织中活性氧自由基水平显著增加,糖原含量显著降低,吡咯列酮改善高脂饮食导致的大鼠肝脏胰岛素抵抗。     

替米沙坦对大鼠非酒精性脂肪性肝炎的保护作用

目的研究替米沙坦对高脂饮食非酒精性脂肪性肝炎（NASH）大鼠的预防和保护作用。方法 35只雄性SD大鼠随机分为正常对照组（NC组,n=10）、模型组（FC组,n=15）和替米沙坦干预组（FT组,n=10）。FC组和FT组高脂饲料喂养16周诱发脂肪性肝炎,其中FT组高脂喂养12周后,给予替米沙坦（5mg.kg-1.d-1）灌胃治疗4周。检测血清丙氨酸氨基转移酶（ALT）、天冬氨酸氨基转移酶（AST）、胆固醇（TC）、三酰甘油（TG）和高密度脂蛋白胆固醇（HDL-C）,测空腹血糖（FBG）和血清胰岛素（FINS）,计算胰岛素抵抗指数（HOMA-IR）,取肝组织测肝指数,病理切片检查和α-SMA免疫组织化学染色观察组织学改变。结果与FC组比较,FT组大鼠肝指数、ALT降低（P〈0.01）,HOMA-IR改善（P〈0.01）,肝星状细胞活化减少,肝脏病理学改善。结论替米沙坦对NASH大鼠有保护和抗肝纤维化的作用。     

2型糖尿病大鼠模型的建立与评价

目的：建立具有胰岛素抵抗特征、发病过程近似于人类2型糖尿病的动物模型。方法：雄性Wistar大鼠喂以富含不饱和脂肪酸的特殊高脂肪膳食5周，诱发出胰岛素抵抗．继之以小剂量链脲佐菌素（STZ，25mg／kg，腹腔注射）导致胰岛素代偿性分泌障碍，诱发高血糖症。应用正常血糖-高血浆胰岛素钳夹技术评价大鼠的胰岛素敏感性。结果：与常规饲料喂养大鼠相比，高脂膳食组的葡萄糖输注率显著降低，空腹血浆胰岛素显著升高。STZ注射后1周高脂膳食组大鼠血糖中度升高，血胰岛素下降，但仍高于普通饲料喂养组，且高脂血症和胰岛素抵抗继续存在。高脂饲料喂养组及高脂饲料＋小剂量STZ注射组大鼠的葡萄糖输注率显著低于正常对照组。结论：通过高脂膳食结合小剂量STZ注射成功复制出了实验性2型糖尿病动物模型，它是研究2型糖尿病发病机制、药物研究和胰岛素抵抗相关疾病的理想动物模型．     

葛根素对胰岛素抵抗大鼠脂肪组织中糖原合成酶激酶3β表达的影响

目的探讨葛根素对高脂饮食诱导的胰岛素抵抗大鼠脂肪组织中糖原合成酶激酶3β(GSK-3β)表达的影响。方法30只SPF级雄性Wister大鼠随机分为2组,正常对照组10只,常规饲料喂养,模型组20只,高脂饲料喂养;4周后模型形成,模型组随机分为2组(胰岛素抵抗组、葛根素干预组,每组10只),继以高脂饲料喂养,葛根素干预组同时给予葛根素注射液100mg·kg-1·d-1腹腔注射。干预6周后,用Western-blot方法检测各组大鼠附睾脂肪组织中GSK-3β的表达,分析对比各组的表达差异;定期检测大鼠体重、空腹血糖及血浆胰岛素、血甘油三酯和胆固醇,并计算胰岛素敏感指数。结果高脂饲料喂养4周后,与正常对照组比较,模型组大鼠体重(BW)、空腹血糖(FPG)、胰岛素(FINS)、胆固醇(TC)、甘油三酯(TG)显著升高(P<0.05或P<0.01),胰岛素敏感指数ISI显著下降(P<0.01),胰岛素抵抗模型诱导成功;葛根素干预6周后,与胰岛素抵抗组大鼠比较,脂肪组织中GSK-3β的表达显著下降(P<0.05),和正常对照组比较,无显著差异。结论葛根素显著下调脂肪组织GSK-3β的表达,并且可能参与其改善胰岛素抵抗的机制。     

高脂喂养法建立大鼠胰岛素抵抗模型

目的建立大鼠胰岛素抵抗模型。方法采用高脂饲料喂养雄性SD大鼠,6周后分别进行葡萄糖耐量试验和胰岛素耐量试验,并测定血清胰岛素、总胆固醇及甘油三脂含量,求算胰岛素敏感性指数。结果与正常对照组相比,3周后喂以高脂饲料的大鼠体重显著增加（P〈0．05,n=15）,6周后葡萄糖耐量和胰岛素耐量明显异常,胰岛素水平显著升高（P〈0．01,n=15）,胰岛素敏感性明显下降（P〈0．01,n=15）,但空腹血糖、血清中总胆固醇和甘油三脂含量无显著改变（P〈0．05,n=8）。结论高脂饲料喂养大鼠6周可出现明显的胰岛素抵抗特征。     

替米沙坦对非酒精性脂肪性肝炎大鼠胰岛素抵抗及氧化应激的影响

目的 探讨替米沙坦对非酒精性脂肪性肝炎(NASH)大鼠血脂及氧化应激及胰岛素抵抗的影响。方法采用随机数字表法将50只雄性SD大鼠随机分为对照组、模型组、多烯磷脂酰胆碱组、替米沙坦低剂量组和替米沙坦高剂量组,每组10只。对照组以普通饲料喂养,模型组和干预组给予高脂饲料喂养诱发NASH,12周后,分别给予生理盐水1.0 m L/(kg·d)、生理盐水1.0 m L/(kg·d)、多烯磷脂胆碱8.4 mg/(kg·d)、替米沙坦4 mg/(kg·d)和替米沙坦8 mg/(kg·d)灌胃4周。所有大鼠在第16周末处死,测肝酶、血脂、氧化应激、胰岛素抵抗指数(HOMA-IR)等及肝组织NAS评分。结果 与模型组比较,多烯磷脂酰胆碱组丙氨酸转氨酶(ALT)、天冬氨酸转氨酶(AST)减低,NAS评分改善;替米沙坦低剂量组AST减低,血清总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-PX)、肝组织SOD和GSH-PX提高,血清及肝组织MDA减低,HOMA-IR减低,NAS评分改善;替米沙坦高剂量组ALT减低,余指标变化同替米沙坦低剂量组。结论 高剂量的替米沙坦可降低NASH大鼠肝酶、氧化应激、胰岛素抵抗和肝脏脂质沉积,且作用优于多烯磷脂酰胆碱及低剂量替米沙坦。     

东宝肝泰对大鼠高脂饮食脂肪性肝炎的预防作用

目的：探讨东宝肝泰对大鼠高脂饮食脂肪性肝炎的预防作用。方法：雄性SD大鼠24只，随机分为3组。正常组予标准饮食喂养；对照组予高脂饮食(普通饲料加20g／kg胆固醇加100g／kg猪油)喂养；预防组在高脂饮食喂养8周后加用东宝肝泰，均于第16周处死。测量大鼠体重、肝湿重、肝指数(肝湿重／体重)及脂肪重量，并测定血清脂质、肝功能和肝匀浆脂肪含量，通过HE染色观察肝细胞脂肪变性、炎症程度。结果：预防组和对照组大鼠均出现肥胖、高脂血症及血清转氨酶升高。与对照组相比，预防组各项指标均有改善趋势，但除血清天门冬酸氨基转移酶(AST)、总胆固醇(TC)外两组间比较并无统计学差异。结论：东宝肝泰对高脂饮食诱发的大鼠高脂血症性脂肪性肝炎可能无预防作用。     

葛根素对胰岛素抵抗大鼠脂肪组织中蛋白激酶B表达的影响

目的 :在高脂饮食诱导胰岛素抵抗的基础上 ,观察葛根素对胰岛素抵抗大鼠脂肪组织中蛋白激酶B蛋白 (PKB)表达的影响。方法 :选取雄性Wistar大鼠 30只 ,随机分为正常对照组 10只 ,给予基础饲料 ;模型组 2 0只 ,给予高脂饲料。模型组大鼠给予高脂喂养 4周后 ,随机分为 2组 :胰岛素抵抗组 ,继续高脂饮食 ;葛根素治疗组 ,继续高脂饮食同时 ,腹腔注射葛根素注射液 (10 0mg·kg-1·d-1)。干预 6周后 ,蛋白印迹法检测大鼠脂肪组织中胰岛素刺激PKB的蛋白表达含量。结果 :4周后 ,高脂喂养鼠的体重、空腹血糖、胰岛素、甘油三脂、胆固醇及胰岛素抵抗指数 (HOMA IR)明显升高 ,胰岛素敏感指数(ISI)显著下降 ,出现了胰岛素抵抗。葛根素治疗 6周 ,大鼠的血糖、胰岛素及HOMA IR下降 ,ISI显著升高。胰岛素抵抗组大鼠脂肪组织中PKB的表达明显减少 ,较对照组下降了 2 3.5 % (P <0 .0 1)。葛根素治疗 6周后 ,大鼠PKB蛋白表达明显升高 ,较胰岛素抵抗组增加了 18.7% (P <0 .0 1)。结论 :葛根素明显改善胰岛素抵抗 ,可能与增加脂肪组织中PKB蛋白表达有关     

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.     

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.