三种蝮蛇抗栓酶的毒性及性质的实验研究

目的:对三种蝮蛇抗栓梅的毒性及其性质进行实验研究。方法:小白鼠尾静脉注射急性毒性实验法和家兔亚急性毒性实验法。结果:三种蝮蛇抗栓酶的毒性强度用LD_50表示,分别是,蛇岛蝮蛇抗栓酶为1.68±0.35u/kg,东北陆生白眉蝮蛇抗栓酶为5.223±0.61u/kg,浙江蝮蛇抗栓酶为1.94±0.15u/kg。对家兔亚急性毒性实验表明,对血细胞、肝及肾功能、脏器等无明显影响。     

蝮蛇抗栓酶对家兔抗凝血作用的药效动力学

<正> 蝮蛇抗栓酶(ahylysantinfarctase)是从东北陆生白眉短尾蝮蛇(Agkistrodon halys brevicaudus Stejneger)毒中分离得到的以精氨酸酯酶为主的酶制剂,具有抗凝和溶纤作用。为了解其iv给药后的药效动力学,本研究以家兔为实验对象,用毛细玻管法测定凝血时间,以给药后凝血时间的延长率为药理效应指标,观察了蝮蛇抗栓酶抗凝作用的量效关系和时效关系,并求出有关参数。结果如下: 1.剂量-效应关系:成年家兔24只,随机分成6组。iv蝮蛇抗栓酶0.15～0.40mg/kg时,其对家兔的抗凝     

三种蝮蛇抗栓酶注射剂对大鼠和家兔血小板聚集的影响

用比浊法研究三种蝮蛇抗栓酶注射剂对大鼠和家兔血小板聚集的影响,结果表明蝮蛇抗栓酶注射剂在试管内浓度0.045u/ml 时对大鼠和家兔血小板聚集无明显抑制作用。静脉注射蝮蛇抗栓酶注射剂1u/kg 对家兔血小板聚集有明显抑制作用。尤其是蛇岛蝮蛇抗栓酶注射剂抑制作用最为显著。     

正交试验法筛选蝮蛇抗栓酶活力测定条件

蝮蛇抗栓酶(ahylysantinfarctase)系从东北陆生白眉短尾蝮蛇(Agkistrodon halys)蛇毒中分得的以精氨酸酯酶为主的酶制剂。临床用于脑血栓、血栓闭塞性脉管炎等疾病。其酶活力测定有紫外法、比色法和荧光     

蝮蛇抗栓酶活力测定方法的研究

蝮蛇抗栓酶注射液是从蛇岛蝮蛇和东北长白山系蝮蛇毒中分离出来的精氨酸酯酶制剂。目前用于治疗脑血栓、血栓性脉管炎等血管疾病,其活力以它对底物 N-对甲苯磺酰—L—精氨酸甲酯(简称 TAMF)的水解反应速度大小表示。本文用紫外法在37℃,257nm 下对不同批号蝮蛇抗栓酶注射液进行测量分别得到酶绝对活力和相对活力为μ=0.234～0.265,μ′=22.73～25.67。     

江浙蝮蛇抗栓酶基础实验及临床应用研究

江浙蝮蛇抗栓酶(SVATE)是在蛇岛蝮蛇抗栓酶研制的基础上进一步研制成功的一种毒性低、疗效高、用途广的抗凝溶栓药物。     

蛇岛蝮蛇抗栓酶注射液技术鉴定会在大连召开

<正> 辽宁蛇岛因盛产蝮蛇而中外闻名,是我国天然的蝮蛇蛇源宝库。为了开发和利用这一天然药物资源,我院与兄弟单位协作共同研制成功了蛇岛蝮蛇抗栓酶注射液,并于一九八一年八月十二至十四日在大连旅顺口召开了技术鉴定会。本品是由蛇岛蝮蛇毒中分离的以精氨酸酯酶为主要成分的无菌酶制剂。技术鉴定会     

短尾蝮蛇毒中磷脂结合抗凝蛋白的急性毒性实验

近年来,国内外的学者们对蝮蛇毒进行大量的研究,了解到蝮蛇毒中主要含有精氨酸酯酶、类凝血酶、激肽释放酶、纤溶酶和磷脂酶A2,并以富含精氨酸酯酶为特征,而类凝血酶、激肽释放酶和纤溶酶一般都具有精氨酸酯酶活力。我国在70年代后期开始研制蛇毒酶制剂,主要作为抗凝剂治疗血栓性疾病。分别有以下几种:东北白眉蝮蛇毒为原料制成的“蝮蛇清栓酶”;以江浙蝮蛇毒为原料制成的“蝮蛇抗栓酶”和以尖吻蝮蛇毒为原料制成的“蕲蛇毒去纤酶”。这几种酶制剂,虽然商品名称不同但均为非纯化成分,主要有效成分均为精氨酸酯酶,纯度不高[1]。本试验对短尾…     

蝮蛇抗栓酶对离体大鼠工作心脏缺血再灌注损伤的作用

<正> 蝮蛇抗栓酶(Viper antithrombotic enzy-me,VAE)是从东北陆生白眉蝮蛇蛇毒中提取的一种酶制剂,实验证明VAE具有降低血浆纤维蛋白原、血液粘度、血小板聚集功能及粘附率、溶解微血栓、扩张血管、改善微循环等作用。临床观察对脑血栓、脑栓塞、血栓闭塞性脉管炎、冠心病、心绞痛、心肌梗塞等具有较好疗效,但是对心脏缺血再灌注损伤是否具有保护作用,尚未见报道。本实验通过     

蝮蛇抗栓酶在治疗非血栓性疾病中的应用

蝮蛇抗栓酶(Ahylysantinfarctase)是从蝮蛇毒中提取的一种酶制剂,临床上主要用于治疗脑血栓、心肌梗塞、闭塞性脉管炎等血管栓塞性疾病。近年临床研究发现,它对多种非血管栓塞性疾病也有较好疗效。现介绍如下。 1 急性一氧化碳中毒性痴呆 急性一氧化碳中毒性痴呆,系指急性一氧化碳中毒经抢救恢复,在数天乃至数周表现基本正常的间歇期后,再度出现以痴呆为主的一组神经精神症状。张福军等用较大剂量精制蝮蛇抗栓酶治疗该病19例,方法为:用1.0u本品     

Effects of molsidomine on coronary artery thrombosis and myocardial ischemia in acute canine experiments

Antithrombotic and hemodynamic properties of molsidomine (0.10 mg/kg i.v.) were evaluated in an in-vivo model of coronary artery thrombosis initiated by electrical stimulation for 6 h. Molsidomine prolonged time to vessel occlusion and prevented heart rate and end-diastolic pressure increase and contractility decrease. Infarct size was smaller after drug treatment related either to left ventricle (P < 0.02) or to vessel area-at-risk (P < 0.01). It is suggested that molsidomine has antithrombotic effects which might prevent acute coronary infarction.     

皖南蝮蛇毒蛋白C激活物的急性毒性作用的研究

目的:探讨蛇毒蛋白C激活物(protein Cactivator,PCA)对大、小鼠的急性毒理反应。方法:大鼠采用上下剂量增减法,小鼠采用半数致死量法,观察实验动物症状、体征、死亡时间和累积死亡率。结果:PCA尾静脉注射大鼠(剂量17.5～175mg/kg)、小鼠(剂量为6.25～11mg/kg)的中毒表现为不同程度的口鼻泡沫状出血、呼吸困难、心率加快、走路不稳、蜷缩、昏厥性抽搐;大、小鼠尾静脉注射PCA的LD50及其95%可信限分别为29.57(17.5～55)mg/kg和8.05(7.55～8.54)mg/kg;大体解剖可见双肺有片块状出血,病理镜检显示出血主要累及肺泡、支气管等。其他器官未见明显异常。结论:皖南蝮蛇毒PCA的毒性主要是抗凝过度导致的出血,肺出血引起的急性呼吸衰竭是实验动物死亡主要原因。     

短尾蝮蛇毒磷脂结合抗凝蛋白对动物血栓的抗栓作用

目的从短尾蝮蛇毒中分离纯化磷脂结合抗凝蛋白(PBAP),研究其对动物血栓的抗栓作用。方法用Chandler法制备家兔体外血栓和半体内血栓模型;用Reyers法制备大鼠静脉血栓模型;用Nowork法制备家兔肺动脉栓塞模型。测定PBAP对家兔体外血栓、半体内血栓、肺动脉栓塞和大白鼠静脉血栓的抗栓效应。结果短尾蝮蛇毒PBAP对家兔体外血栓、半体内血栓、肺动脉栓塞和大白鼠静脉血栓干湿重均有明显减轻作用,与生理盐水对照组比较,差异均有统计学意义(P<0.05或P<0.01)。结论PBAP抗凝蛋白对动物血栓具有明显的抗栓作用,具有潜在的临床应用价值。     

The Effects of Maternally–administered Morphine on Rat Foetal Development and Resultant Tolerance to the Analgesic Effect of Morphine

Groups of 6–9 pregnant (sperm = Day 1) Sprague-Dawley (Simonsen) rats were injected with morphine sulphate, 20 mg/kg subcutaneously, on gestational days 2–5, 7–9 or 11–13. Pups delivered by Caesarian section on gestational day 22 were essentially free of any observable teratogenic changes including bone defects. However, offspring of morphine-treated rats (20 mg/kg/day subcutaneously on gestational days 17, 18, 19 and 20) which were allowed to litter normally exhibited on day 12–13 a significantly (P < 0.05) decreased response to a nocioceptive (55° surface) stimulus 30 min. following an injection of morphine sulphate 0.45 mg/kg subcutaneously (offspring of morphine-treated mothers, 16.8 sec. ± 2.3 S.E.M. versus control offspring, 25.2 sec. ± 1.7 S.E.M.). On days 21–22 of age larger doses of morphine were required to elicit an analgesic response in the young. Following an injection of morphine sulphate, 10 mg/kg subcutaneously, the maternal animals also showed significant reduction in reaction time 30 minutes later (treated, 7.6 sec. ± 0.6 S.E.M. versus control, 16.1 sec. ± 0.6 S.E.M.) and 60 minutes later (treated, 7.5 sec. ± 0.9 S.E.M. versus control, 20.8 sec. ± 2.9 S.E.M.) as compared to paired waterinjected control pregnant animals.     

Antithrombotic activity of AT-1015, a potent 5-HT(2A) receptor antagonist, in rat arterial thrombosis model and its effect on bleeding time.

The antithrombotic activity of N-[2-(4-(5H-dibenzo[a,d]cyclohepten-5-ylidene)piperidino)ethyl]-1-formyl-4-piperidinecarboxamide monohydrochloride monohydrate (AT-1015; a 5-HT(2A) receptor antagonist) was studied in a photochemically induced arterial thrombosis (PIT) model in the rat femoral artery, and in the tail transection bleeding time test. Ticlopidine (an antiplatelet agent) and sarpogrelate (a selective 5-HT(2A) receptor antagonist) were studied as reference compounds. Pretreatment with AT-1015 (1 mg/kg, p.o.) significantly prolonged the time required to occlusion of the artery with thrombus, and the effect (3 mg/kg, p.o.) persisted for 24 h with significant inhibition of 5-HT-induced vascular contraction. Ticlopidine and sarpogrelate also significantly prolonged the time to occlusion at 100 mg/kg, p.o. Sarpogrelate (300 mg/kg, p.o.) showed the similar antithrombotic efficacy to AT-1015 (3 mg/kg, p.o.), while the effect disappeared within 6 h. No significant bleeding time prolongation was observed at 10 mg/kg of AT-1015, which is 10 times higher than the antithrombotic effective dose; whereas ticlopidine significantly prolonged bleeding time at the same dose as the antithrombotic effective dose. These results suggested that AT-1015 is a potent and long-acting oral antithrombotic agent in this model, which may be elucidated by its potent and long-acting inhibition of vasoconstriction through 5-HT(2A) receptor.     

Interaction of Viagra with the NO donors molsidomine and RE 2047 with regard to antithrombotic and blood pressure lowering activities.

After p.o. administration to rats in doses up to 30 mg/kg, Viagra showed no antithrombotic effect. However, it enhanced the inhibition of thrombus formation by RE 2047 from 9% to 17% (5 + 5 mg/kg) or 19% to 27% (10 + 10 mg/kg) in arterioles. This effect was even more obvious in venules where an inhibition of 9% (5 + 5 mg/kg) or 15% (10 + 10 mg/kg) was seen whereas the individual drugs had no effect. The antithrombotic activity of molsidomine was not altered. The blood pressure (b.p.) of spontaneously hypertensive rats was reduced by the combination of Viagra and RE 2047 (5 + 5 mg/kg) to 94% of normal after 2 h while the individual drugs had no effect at this dose. The coadminstration of 10 mg/kg of each drug reduced the b.p. to 87% of normal. The combination of Viagra with molsidomine decreased b.p. to 84% (5 + 5 mg/kg) or 79% (10 + 10 mg/kg), respectively.     

Adrenaline toxicity in mice: sensitization of alpha 1 adrenoreceptors by nitroglycerin

In mice, injected subcutaneously with nitroglycerin (GTN) for 12 days, adrenaline exhibited an increased toxicity. The LD50 value for adrenaline in control animals was 11.1 mg/kg b.wt. In GTN-treated animals the LD50 value for adrenaline, measured 3 days after the last injection of GTN, was 9.1 mg/kg b.wt. (P = 0.05). In the animals sensitized with GTN, the adrenergic alpha-receptor blocker phentolamine (1 or 10 mg/kg b.wt.) protected from the lethal action of adrenaline (P = 0.06 and P = 0.001, respectively). A low dose (1 mg/kg b.wt.) of the adrenergic beta receptor blocker propranolol, was without effect while a higher dose (10 mg/kg b.wt.) potentiated the toxicity of adrenaline (P = 0.007). The alpha 1 adrenoreceptor antagonist, prazosin, (1 or 10 mg/kg b.wt.) was found to be highly effective in protecting the GTN-sensitized mice towards adrenaline (P = 0.003 and P = 0.001, respectively). By contrast, the alpha 2 adrenoreceptor antagonist, yohimbine, (1 or 10 mg/kg b.wt.) was much less effective (P = 0.988 and P = 0.111, respectively). It is concluded that the lethal action of adrenaline was caused by stimulation of alpha 1 adrenoreceptors, and that long term treatment with GTN caused a sensitization of these receptors in mice. The possible relevance of this finding for the reported withdrawal symptoms and sudden death phenomenon in nitroglycerin-exposed industrial workers is discussed.     

The protective effect of selenium in cisplatin-related retinotoxicity

Purpose: The aim of this study is to evaluate the retinal toxicity of cisplatin and neuroprotective effect of selenium in cisplatin-related retinal toxicity.

Methods: Eighteen adult Wistar-Albino rats were divided into three groups. Group 1 (n?=?6) received intraperitoneal (i.p.) injection of 2.5?ml physiologic saline for three days, group 2 (n?=?6) received i.p. 16?mg/kg cisplatin for three days and group 3 (n?=?6) received i.p. 16?mg/kg cisplatin for three days and 1.5?mg/kg twice daily selenium via gavage five days prior to cisplatin injection and for three days concomitantly with cisplatin injections. The total retinal thickness, outer nuclear layer (ONL), inner nuclear layer (INL) and inner plexiform layer (IPL) thicknesses were measured in hematoxylin/eosin and apoptotic index (AI) of ganglion cell layer (GCL) and INL was evaluated in TdT-mediated dUTP-biotin nick end labeling (TUNEL)-stained retina sections.

Results: Selenium statistically succeeded to reduce total retinal thickness in cisplatin-toxicated retinas: from 210.17?±?23.40 to 173.55?±?20.43, ONL: 49.79?±?5.32 to 41.87?±?6.30, INL: 33.72?±?7.93 to 25.06?±?5.73 and IPL: 53.61?±?8.63 to 45.61?±?6.92?µm in hematoxylin/eosin-stained retina sections. The AI was also reduced in INL (30.10?±?12.02 to 19.48?±?12.99) and in GCL (37.59?±?17.70 to 33.15?±?13.78). However, statistical significance was present in only AI values of INL.

Conclusions: Selenium limited edema due to the toxicity and reduced the retinal thickness and showed neuroprotection in cisplatin-induced retinotoxicity.     

Efficacy of Aerosolized Celecoxib Encapsulated Nanostructured Lipid Carrier in Non-small Cell Lung Cancer in Combination with Docetaxel

Purpose

Evaluation of in-vivo anticancer activity of aerosolized Celecoxib encapsulated Nanolipidcarriers (Cxb-NLC) as a single therapeutic agent and combined with intravenously administered Docetaxel (Doc) against non-small cell lung cancer.

Methods

Cxb-NLC were prepared by high-pressure homogenization and were characterized for its physicochemical characteristics. Metastatic A549 tumor model in Nu/Nu mice was used to evaluate response of aerosolized Cxb-NLC & Doc. Isolated lung tumor samples were analyzed for: a) DNA fragmentation and cleaved caspase-3 by immunohistochemistry, b) apoptotic and angiogenic protein markers by western blot, c) global proteomic alterations by an isobaric labeling quantitative proteomic method and d) toxicity studies of NLC.

Results

The particle size of Cxb-NLC was 217?±?20 nm, while entrapment efficiency was more than 90%. Cxb-NLC and Doc alone and in combination showed 25?±?4%, 37?±?5%, and 67?±?4% reduction in tumor size respectively compared to control. Proteomic analysis with combination treatment further revealed significantly decreased expression of multiple pro-survival and pro-metastasis proteins as well as tumor invasion markers and the expression of S100 family proteins, such as S100A6 and S100P were decreased by 2.5 and 1.6 fold.

Conclusions

Combination therapy with Cxb-NLC and Doc showed significant reduction in tumor growth which was further confirmed by proteomic analysis.     

Adrenaline Toxicity in Mice: Sensitization of α1 Adrenoreceptors by Nitroglycerin

Abstract: In mice, injected subcutaneously with nitroglycerin (GTN) for 12 days, adrenaline exhibited an increased toxicity. The LD50 value for adrenaline in control animals was 11.1 mg/kg b.wt. In GTN-treated animals the LD50 value for adrenaline, measured 3 days after the last injection of GTN, was 9.1 mg/kg b.wt. (P = 0.05). In the animals sensitized with GTN, the adrenergic α-receptor blocker phentolamine (1 or 10 mg/kg b.wt.) protected from the lethal action of adrenaline (P = 0.06 and P = 0.001, respectively). A low dose (1 mg/kg b.wt.) of the adrenergic β receptor blocker propranolol, was without effect while a higher dose (10 mg/kg b.wt.) potentiated the toxicity of adrenaline (P = 0.007). The α₁ adrenoreceptor antagonist, prazosin, (1 or 10 mg/kg b.wt.) was found to be highly effective in protecting the GTN-sensitized mice towards adrenaline (P = 0.003 and P = 0.001, respectively). By contrast, the α₂ adrenoreceptor antagonist, yohimbine, (1 or 10 mg/kg b.wt.) was much less effective (P = 0.988 and P = 0.111, respectively). It is concluded that the lethal action of adrenaline was caused by stimulation of α₁ adrenoreceptors, and that long term treatment with GTN caused a sensitization of these receptors in mice. The possible relevance of this finding for the reported wihdrawal symptoms and sudden death phenomenon in nitroglycerin-exposed industrial workers is discussed.