抗痫灵对大鼠杏仁核点燃效应的拮抗作用

用大鼠杏仁核点燃模型研究了抗痫灵的抗癫痫作用。每日1次电刺激杏仁基底外侧核可在第15d产生点燃效应的5期反应,刺激后放电显著延长。抗痫灵在未产生中枢镇静的剂量就能抑制点燃效应的5期反应,ED_(50)为84.7mg/kg,对刺激后放电影响较少。丙戊酸钠抑制5期反应作用较强,并能显著缩短刺激后放电时程。实验表明抗痫灵具有对抗慢性杏仁核点燃效应的作用。     

盐酸关附甲素注射液对实验性心律失常的作用

关附甲素是从关白附子块根中提取的一种新生物碱。实验表明IGFAH(50　g/ml)对大鼠离体心脏结扎冠脉诱发的室性心律失常有明显的保护作用,IGFAH3、6、12mg/kgiv能显著提高电刺激麻醉兔心室致颤阈值,IGPAH13.4,16.8,21.0mg/kgiv能明显对抗Cal₂-Ach液诱发小鼠房扑(颤),其ED₂为12.4±1.5mg/kg。IGFAH10,25,40mg/kgiv对乌头碱诱发的大鼠室性心律失常有明显的保护作用。IGFAH小鼠iv的LD₅₀为163.9mg/kg,其96%可信限为151.9—176.7mg/kg。     

托吡酯对大鼠点燃过程及杏仁核后放电的影响

目的观察托吡酯对大鼠点燃过程及杏仁核后放电的影响。方法选取雄性健康Wistar大鼠60只随机分为实验组及对照组各30只,实验组用托吡酯(40mg/kg)进行灌胃,用相同电刺激强度对两组大鼠进行点燃,记录点燃所需刺激次数、杏仁核后放电阈值、后放电时程及后放电频率。结果托吡酯(40mg/kg)灌胃后,实验组大鼠点燃总数明显减少,点燃所需刺激次数显著增加,杏仁核后放电阈值升高,时程缩短,后放电频率减少。结论托吡酯可明显抑制大鼠点燃过程,缩短杏仁核后放电时程和减少放电频率,升高杏仁核后放电阈值。     

选择性κ阿片激动剂K-Ⅱ与U-50488的药理作用比较

K-Ⅱ系k阿片激动剂U-50488的同类物。通过部分离体和整体实验比较了K-Ⅱ与U-50488的药理作用。实验发现,K-Ⅱ抑制电刺激兔输精管收缩的IC₅₀值为0.42 nmol/L,U-50488为26.5 nmol/L;K-Ⅱ抑制小鼠运动功能(横筛法)的ED₅₀值为1.7 mg/g,U-50488为15.3 mg/kg;K-Ⅱ的小鼠LD₅₀值为152.5 mg/kg,U-50488为118.4 mg/g;K-Ⅱ明显降低小鼠自发活动的作用比U-50488强5倍。结果表明,K-Ⅱ是一个药理作用较U-50488强的k受体激动剂。     

双氢青蒿素对小鼠抗疟作用的药效动力学

双氢青蒿素(DHA)是青蒿素的一种还原产物,对感染伯氏疟原虫ANKA株的小鼠一次im给药,其抗疟作用的量—效关系和时—效关系可分别用y=4.9960+2.9536x和y=7.2654-0.3414t表达,进而估算出其ED₅₀和ED₅₀分别为1.00±0.13 mg/kg和2.72±0.70 mg/kg以DHA 5.0 mg/kg im后其药效下降一半的时间为6.6 h,体内有效药量的消除速率常数k为0.2662 h^-1,效量半衰期为2.6 h。式中y为机率单位,是DHA对疟原虫抑制作用的估算值,x为对数剂量,t为DHA im后的间隔时间。     

7-甲氧基-4′-羟基-3′-二乙胺甲基异黄酮(MHDF)对大鼠血流动力学和主动脉的作用

本实验观察了MHDF对整体大鼠血流动力学和离体大鼠胸主动脉的作用。结果表明iv MHDF(3～12.8 mg/kg)能降低大鼠左心室±dp/dt_max,V_max,V_pm和LVSP,延长T-dp/dt_max,减慢心率。MHDF还能舒张大鼠胸主动脉,ED₅₀为6.5×10^-6mol/L;非竞争拮抗NA和CaCl₂致主脉收缩,pD₂′为3.11±0.21和3.73±0.07;抑制高K⁺致主动脉收缩,IC₅₀为1.76×10^-5mol/L。提示MHDF对血管的作用与α受体阻断剂不同,而可能与钙拮抗有关。     

莨菪碱衍生物与M胆碱受体相互作用的构效关系

本文研究了一系列东莨菪碱衍生物对³H-QNB与大鼠脑M受体特异结合的影响。并通过比较它们的IC₅₀(用结合实验),药物—受体相互作用的解离常数K_B(抗乙酰胆碱引起的回肠收缩)以及抗震颤和抗匹罗卡品引起小鼠流涎的ED₅₀,分析了它们的构效关系。结果表明,K_B值与IC₅₀有很好的相关性(r=0.977),其线性回归的斜率为1.047;IC₅₀与抗震颤作用的ED₅₀之间相关性差,而log IC₅₀/ED₅₀值与它们的分配系数(logP)相关好(r=0.971),10号化合物的分配系数最大,中枢作用的选择性也最强。抗流涎ED₅₀与IC₅₀的相关系数为0.827。     

艾叶油的呼吸系统药理研究-Ⅱ,抗过敏作用

目的:本文研究艾叶油的抗过敏作用。方法:采用致敏豚鼠气管Schultz-Dale 反应,组胺或氨甲酰胆碱引起的豚鼠气管收缩,大鼠被动皮肤过敏,5-羟色胺引起的大鼠皮肤毛细血管通透性增强,豚鼠肺组织释放过敏性慢反应物质(SRS-A) ,SRS-A 收缩豚鼠回肠等试验。结果:艾叶油抑制致敏豚鼠气管Schultz-Dale 反应(IC₅₀ :98 .6mg/L) ;100mg/L 明显降低组胺或氨甲酰胆碱引起的豚鼠气管收缩pD₂ 值;明显抑制大鼠被动皮肤过敏(ID₅₀ :0 .22g/kg) 和5 羟色胺引起的大鼠皮肤毛细血管通透性增强反应(ID₅₀ :0 .52g/kg) ;抑制豚鼠肺组织释放SRS-A(IC₅₀ :49 .7mg/L) ;拮抗SRS-A 对豚鼠回肠的收缩(IC₅₀ :34 .9mg/L) 。结论:艾叶油具有抗过敏作用,对呼吸道过敏反应有保护作用,是其治疗支气管哮喘和慢性气管炎作用机制之一     

2-乙酰氧基-5-乙酰氨基苯甲酸的合成及镇痛抗炎作用

目的　合成2-乙酰氧基-5-乙酰氨基苯甲酸并进行镇痛、抗炎作用的初步研究。方法　以水杨酸和苯胺为原料,经重氮、偶合、还原及酰化合成目标化合物,化学结构经元素分析、IR和¹H-NMR确定;采用小鼠醋酸扭体、耳部肿胀法研究镇痛和抗炎作用。结果　目标化合物的熔点为170～173℃,中和法测含量99.2% ,收率42.7% (以水杨酸计)。小鼠灌胃后抑制醋酸所致疼痛的ED₅₀为1.2mmol/kg ,抑制二甲苯所致耳廓炎症的ED₅₀为2 .3mmol/kg ,LD₅₀为2598mg/kg。结论　2-乙酰氧基-5-乙酰氨基苯甲酸合成简单,收率稳定,具有比阿司匹林和对乙酰氨基酚更强的镇痛和抗炎作用。     

克班宁急性毒性与抗心律失常活性的初步研究

目的研究克班宁(crebanine,Cre)的急性毒性与抗心律失常作用。方法以改良寇氏法考察小鼠静注LD₅₀,以BaCl₂致大鼠心律失常模型观察Cre的治疗与预防作用。结果LD₅₀为9.382mg/kg,95%可信限为8.314～10.600mg/kg;治疗组与预防组iv Cre2.5mg/kg可使大鼠恢复窦律,与对照(生理盐水)组相比,差异有显著性意义。结论Cre有一定的毒性,对大鼠实验性心律失常具有治疗与预防作用。     

Inhibition by antiepileptics of carbachol but not lithium- or 5-methoxytryptamine-induced wet dog shakes in rats

The influence of antiepileptic drugs on the wet dog shakes (WDS) induced by intracerebroventricular injections of carbachol (30 micrograms icv) was investigated in rats. Diphenylhydantoin (DPH, 8 and 4 mg/kg), diazepam (0.4, 0.2 and 0.1 mg/kg), phenobarbital (12.5, 6.25 and 3.12 mg/kg), sodium valproate (Depakine, 200, 100 and 50 mg/kg) and trimethadione (200, 100 and 50 mg/kg) given ip inhibited the WDS in a dose-dependent manner. These drugs at the same doses did not change the intensity of shaking behavior induced by lithium chloride or 5-hydroxytryptamine. As the antiepileptic drugs tested in these experiments did not have anticholinergic activity and at used doses were not able to prevent electrical convulsions or pentetrazol-induced seizures, it appears that carbachol-induced WDS could be connected with convulsive activity and could be the initial stage of seizures.     

北沙参多糖的免疫抑制活性

北沙参为伞形科珊瑚属植物珊瑚菜(Glehnia littoralis F.Schmidt ex Mig.)的根,是一种常用中药,具有养阴清肺功能。据报道北沙参可延长家兔抗甲胎球蛋白抗体的存在时间。不少植物多糖,如人参、黄芪、刺五加和当归等的多糖成分,对机体的免疫功能有促进作用。为此我们观察了北沙参的多糖成分对机体免疫功能的影响。     

Anti-seizure efficacy of nimodipine in pentylenetetrazole and kainic acid combined seizure models in mice

The present study aimed at establishing two models of experimental seizures by combination treatment with subconvulsive doses of PTZ and kainic acid in adult male mice and evaluating the modulatory role of cerebroselective dihydropyridine calcium channel blocker, nimodipine. The CD50 +/- SEM value for PTZ was found to be 20.00 +/- 0.92 mg/kg, ip in kainic acid (administered at per se subconvulsive dose of 1.00 mg/kg, ip) pretreated mice while CD50 +/- SEM value for kainic acid was found to be 0.30 +/- 0.08 mg/kg, ip in PTZ (administered at per se subconvulsive dose of 30.00 mg/kg, ip) pretreated mice. Nimodipine (5.00 mg/kg, ip) significantly protected the mice from seizure in both of the combination in vivo seizure models. The results suggested synergistic interaction between PTZ and kainic acid at subconvulsive dose combination while the protective efficacy of nimodipine suggested the role of calcium ion as an important mediator for the genesis of seizures.     

Effects of three calcium channel antagonists (amlodipine, diltiazem and verapamil) on the protective action of lamotrigine in the mouse maximal electroshock-induced seizure model

The aim of this study was to assess the effect of three calcium channel antagonists (amlodipine, diltiazem and verapamil) on the anticonvulsant action of lamotrigine (a second generation antiepileptic drug) against maximal electroshock-induced seizures in mice. Results indicated that all three calcium channel antagonists when administered alone [amlodipine (up to 20 mg/kg, ip), diltiazem (up to 10 mg/kg, ip) and verapamil (up to 20 mg/kg, ip)], did not significantly affect the threshold for maximal electroconvulsions in mice. However, amlodipine at a non-protective dose of 20 mg/kg, ip significantly enhanced the anticonvulsant activity of lamotrigine in the maximal electroshock-induced seizure test in mice by reducing its ED(50) value from 6.33 to 2.87 mg/kg (p < 0.05). In contrast, amlodipine at lower doses of 5 and 10 mg/kg, ip, diltiazem (at doses up to 10 mg/kg, ip) and verapamil (at doses up to 20 mg/kg, ip) had no significant impact on the antiseizure action of lamotrigine in the maximal electroshock-induced seizure test in mice. In conclusion, one can ascertain that the favorable combination of lamotrigine with amlodipine deserves more attention from a clinical viewpoint because of the enhanced antiseizure action of lamotrigine.     

Histidine enhances carbamazepine action against seizures and improves spatial memory deficits induced by chronic transauricular kindling in rats

AIM: To investigate whether histidine can enhance the anticonvulsant efficacy of carbamazepine (CBZ) and simultaneously improve the spatial memory impairment induced by transauricular kindled seizures in Sprague-Dawley rats. METHODS: Chronic transauricular kindling was induced by repeated application of initially subconvulsive electrical stimulation through ear-clip electrodes once every 24 h until the occurrence of 3 consecutive clonic-tonic seizures. An 8-arm radial maze (4 arms baited) was used to measure spatial memory, and histamine and gamma-amino-butyric acid levels were measured by high performance liquid chromatography (HPLC). RESULTS: Chronic transauricular kindling produced a significant impairment of spatial memory and a marked decrease in histamine content in the hypothalamus, the brainstem, and the hippocampus. Injection of histidine (1000 mg/kg or 1500 mg/kg, ip) significantly inhibited transauricular kindled seizures. Injection of histidine at lower doses (200 mg/kg or 500 mg/kg, ip) had no appreciable anticonvulsant effect when administered alone, whereas it significantly potentiated the protective effects of CBZ against kindled seizures. CBZ had no ameliorative effect on memory deficit, but, in contrast, histidine (200 mg/kg or 500 mg/kg, ip) alone or co-administered with CBZ significantly ameliorated the memory deficits induced by the seizures. CONCLUSION: Chronic transauricular kindling is a very useful animal model for evaluating memory deficits associated with epilepsy, and histidine has both a potentiate effect on the anticonvulsant efficacy of CBZ and an ameliorative effect on the spatial memory deficits induced in this model. Histidine at a specific dosage range might serve as a beneficial adjuvant for the clinical treatment of epilepsy, especially when accompanied by impaired spatial memory.     

Anticonvulsant properties of flunarizine on reflex and generalized models of epilepsy

The anticonvulsant activity of 1-bis(4-fluorophenyl)methyl-4-(3-phenyl-2-propenyl)-piperazine, flunarizine, was studied after intraperitoneal administration in DBA/2 mice (seizures induced by sound), intravenous administration in Papio papio (myoclonus induced by photic stimulation) and oral administration in Wistar rats (seizures induced by cefazolin). Protection against sound-induced seizures was observed after intraperitoneal administration of flunarizine (5-40 mg/kg). The ED50 for suppression of tonic, clonic and wild running phases of sound-induced seizures was 3.3, 9.8 and 17.5 mg/kg, respectively. This protective action was significantly reduced by pretreatment with aminophylline (50 mg/kg, i.p.). In photosensitive baboons flunarizine (0.5-1.0 mg/kg, i.v.) provided partial protection against myoclonic responses to stroboscopic stimulation. After flunarizine (2 mg/kg, i.v.) this protection lasted for more than 5 hr (and was complete at 2-3 hr). Cefazolin-induced seizures in rats were prevented by administration of flunarizine (20-40 mg/kg, orally). The ED50 for the suppression of tonic and clonic seizures evoked by subsequent intravenous administration of cefazolin was 25 mg/kg. The protective effects of flunarizine (40 mg/kg, orally) were maximal after 3-6 hr and were maintained for 16-24 hr. Behavioural effects of flunarizine included signs of sedation in both mice and rats. Tolerance to the antiepileptic effects of flunarizine was not seen after chronic treatment in rats. The role of purinergic receptors and of calcium entry blockade in the anticonvulsant action of flunarizine requires further study.     

Nifedipine has paradoxical effects on the development of kindling but not on kindled seizures in amygdala-kindled rats

The effects of nifedipine, an antagonist of voltage-operated calcium channels, on the development of amygdala kindling and on the production of fully kindled seizures, stimulated from the amygdala, were investigated. Rats were treated daily with two doses (5 and 50 mg/kg, i.p.) of nifedipine during the development of kindling. Both doses of nifedipine retarded the development of kindled seizures and 50 mg/kg of nifedipine prolonged the latency to the occurrence of bilateral forelimb clonus. In contrast to these antiepileptogenic effects, however, both doses also increased the duration of afterdischarge. This resulted in a striking increase in the cumulative duration of afterdischarge, required to reach stage 4 and 5 seizures. Contrary to the results of a previous study, 50 mg/kg of nifedipine did not produce any significant effect on fully kindled seizures, regardless of the interval (5 min-24 hr) between injection and stimulation of kindling. These results suggested that although nifedipine inhibited the propagation processes of seizures during development of kindling, it appeared to increase the duration of epileptic activity at the kindling focus.     

利血平与优降宁对动物痛阈和吗啡镇痛作用影响因素探讨

采用三种测痛方法,观察了利血平、优降宁对小鼠、大鼠正常痛阈和吗啡镇痛作用的影响,结果表明:ip利血平2 mg/kg,优降宁100 mg/kg均能明显抑制小鼠扭体反应;ip利血平1 mg/kg能明显提高小鼠热板反应时间,但ip优降宁75 mg/kg无明显影响;ip利血平6 mg/kg,优降宁75 mg/kg对大鼠甩尾反应时间均无明显影响;利血平(小鼠0.5～1.0 mg/kg,大鼠2 mg/kg ip)能明显对抗吗啡镇痛作用;优降宁(小鼠35 mg/kg,大鼠50 mg/kg ip)能明显增强吗啡镇痛作用,并能“逆转”利血平对抗吗啡镇痛作用。其“逆转”作用的强弱取决于利血平、优降宁给药的先后次序。     

利血平与优降宁对动物痛阈和吗啡镇痛作用影响因素探讨

采用三种测痛方法,观察了利血平、优降宁对小鼠、大鼠正常痛阈和吗啡镇痛作用的影响,结果表明:ip利血平2 mg/kg,优降宁100 mg/kg均能明显抑制小鼠扭体反应;ip利血平1 mg/kg能明显提高小鼠热板反应时间,但ip优降宁75 mg/kg无明显影响;ip利血平6 mg/kg,优降宁75 mg/kg对大鼠甩尾反应时间均无明显影响;利血平(小鼠0.5～1.0 mg/kg,大鼠2 mg/kg ip)能明显对抗吗啡镇痛作用;优降宁(小鼠35 mg/kg,大鼠50 mg/kg ip)能明显增强吗啡镇痛作用,并能“逆转”利血平对抗吗啡镇痛作用。其“逆转”作用的强弱取决于利血平、优降宁给药的先后次序。