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1.
非寄生凝集素的分离和性质研究   总被引:1,自引:0,他引:1  
采用酸处理Sepharose 6B亲和层析和SephacrylS-200凝胶过滤,首次从中药北寄生中分得一种有毒凝集素,称为北寄生凝集素(Viscum coloratum lectin,VCL),是一种高毒性的植物毒蛋白,对小鼠静脉给药的LD50为4.4ug/kg,其粗提物也具有很强的毒性,对小鼠腹腔给药的LD50为0.2g/kg,分子量52 000,等电点10.5。  相似文献   

2.
目的 研究眼镜蛇神经毒素 ( Cobra neurotoxin, N T) 的急性毒性和蓄积毒性。方法 测 N T 对小鼠的 L D50 ; 对大鼠、狗的1 次性最小中毒剂量和最大安全剂量; 计算 N T 在小鼠、狗体内的24h 蓄积率。结果  N T 经静注、肌注、腹腔、皮下 4 种途径给药对小鼠的 L D50 分别是 (195±95) μg/kg、(156±85) μg/kg、(151±19) μg/kg、(184±85) μg/kg, 对小鼠的最小致死剂量为975μg/kg。 N T 对大鼠、狗的1 次性中毒剂量分别为54μg/kg 和34μg/kg。对小鼠、大鼠和狗的安全剂量分别为815μg/kg、42μg/kg和30μg/kg, 分别约为人临床用剂量 (70μg/50kg·d- 1 ) 的582、30 和21 倍。 N T 在小鼠、狗体内的24h蓄积率分别为 57% 和30% 以上。结论  N T 在使动物中毒的剂量下有广泛的安全范围; N T 在动物体内存在弱蓄积毒性。  相似文献   

3.
烟碱对氧化震颤素和槟榔碱流涎作用的调节   总被引:1,自引:0,他引:1  
氧化震颤素和槟榔碱激动唾液腺M受体剂量依赖性地诱发小鼠流涎,ED_(50)值分别为116.27±20.11μg/kgsc和9.02±1.75mg/kgsc。烟碱(0.5,1.0mg/kgsc间隔5min)预处理后,氧化震颤素和槟榔碱诱发小鼠流涎作用的量效曲线显著左移,ED_(50)值分别降为43.25±11.52μg/kgsc和4.75±0.76mg/kgsc。以美加明阻断N受体功能后,能对抗烟碱调节M受体激动剂的流涎作用。以氯化锂抑制肌醇磷酸酶后,能增强烟碱调节M激动剂的流涎作用。提示烟碱增强唾液腺M受体对其激动剂的反应性和敏感性,可能与神经元性N受体干扰唾液腺磷脂酰肌醇代谢有关。  相似文献   

4.
Pb~(+2)、Cd~(+2)、Hg~(+2)对蚕豆(Vicia faba L.)乳酸脱氢酶的影响   总被引:5,自引:1,他引:4  
段昌群  王焕校 《生态学报》1998,18(4):413-417
Pb^+2,Cd^+2,Hg^+2浓度分别小于5.00mg/kg,2.00mg/kg,0.50mg/kg时,蚕豆(ViciafabaL.)乳酸脱氢酶(LDH)的活性主于对照组,当处理剂量分别长高超过上述剂量时,LDH活性显著地降低,分析不同污染处理条件下LDH同工酶,发现其5种同工酶在不同金属以及同一金属的不同剂量处理条件下,有差异表达的特性,其中LDH2在小剂量重金属作用下被诱导表达;LDH4对  相似文献   

5.
尖吻蝮蛇毒内一种新的抗血小板凝集蛋白agkisacuta …   总被引:1,自引:0,他引:1  
从皖南尖吻蝮蛇毒中经阴离子交换层析和凝胶过滤层析分离纯化离纯化得到抗血小板凝集蛋白agkisacutacin,纯化的agkisacutacin由分子量为14kD和15kD的2条肽链通过二硫键连接,能有效抑制ristocetin诱导的血小板凝集(IC50为18.5mg/L),能轻微抑制凝血酶诱导的血小板聚集(IC50为1.22g/L),但对ADP、胶原诱导的血小板聚集无影响。agkisacutaci  相似文献   

6.
用氰戊菊酯对来自阳谷的棉铃虫(YG)Heliothisarmigera(Hubner)进行抗性品系的筛选。在15代期间经过9代的室内选育,获得抗性品系(Fen-R),抗性倍数高达2463倍,筛选后F1,代LD50值(24.1412g/头)比筛选前F1代LD50值(0.2020 g/头)提高了119.5倍。对来自偃师的棉铃虫(YS)进行了连续两代单对筛选,得到敏感品系(Fen-S),敏感品系的LD50值为0.0116g/头,接近1983年东台敏感品系的LD50值(0.0098g/头)。Fen-R抗性品系筛选前后分别测定了七种杀虫剂的剂量-死亡回归线,发现Fen-R抗性品系对溴氰菊酯[LD50(Fen-R)LD50(YG)=5.2X]和氯氰菊酯(2.5X)具有一定程度的交互抗性;而对功夫菊酯(0.66X),氯菊酯(0.87X)、灭多威(0.74X)及久效磷(1.5X)没有交互抗性。氰戊菊酯加Pb的增效试验结果表明棉铃虫对氰戊菊酯的抗性主要是由于多功能氧化酶的代谢作用。毒理学资料还暗示抗性为多因子(基因)的。  相似文献   

7.
新生期注射纳洛酮和脑啡肽对幼年大鼠分辨学习的影响   总被引:6,自引:1,他引:5  
本文用Spraque-Dawley大鼠为实验动物,从生后一日龄起每日皮下分别注射1次纳洛酮(10,50,100,200μg/100gb.w)、甲硫氨酸脑啡肽(MEK)(20μg/100gb.w),对照组注射等量的生理盐。连续注射14d,观察16日龄幼鼠的吸乳迷津分辨学习(ADL)、30日龄幼鼠的Y迷津明暗分辨学习(BDL)行为与45日龄幼鼠前脑蛋白含量的变化,结果表明,50μg/100gb.w纳洛  相似文献   

8.
本文应用离子交换柱层析和凝胶过滤技术从福建产圆斑蝰蛇泰国亚种蛇毒中纯化出一个新的PLA,(PLA2-3)。经聚丙烯酰胺凝胶电泳,SDS-聚丙烯酰胺凝胶电泳和Ouchterlony双向免疫扩散证明为均一蛋白质。其理化及酶学性质如下:由约120个氨基酸残基组成(不包括半胱氨酸和色氨酸);分子量为14800;等电点为7.8;PLA2酶比活力用自动电位滴定法测定为255μmol/min·mg,用间接溶血法测定半数溶血量(HU50)在家兔和大白鼠分别为0.025μg/ml和0.05μg/ml;小鼠静脉注射的近似LD50为3154mg/kg。与从该蛇毒中分离出的毒性和碱性PLA,相比,具有PLA。酶比活力高,毒性小的特点。此酶具有明显降压作用。抗血小板聚集效应和可逆性负性心肌收缩力作用,但未观察到心肌挛缩现象.  相似文献   

9.
红树植物秋茄幼苗对镉耐性的研究   总被引:30,自引:4,他引:26  
郑逢中  林鹏  郑文教 《生态学报》1994,14(4):408-414
土培和砂培相结合,以不同镉浓度处理秋茄幼苗的试验结果表明:100mg/L镉浓度对种苗萌发产生显著抑制效应;第2对叶萌发百分率在13.3%以下,在幼苗生长阶段,砂培25mg/L组,幼菌苗(植物体平均镉含量146.43μg/g)受严重伤害致死;土培25mg/kg,幼苗(镉含量27.24μg/g)生和工正常;达50mg/kg 时,幼苗(镉含量30.47μg/g)生长明显受抑制, 生物量和高度生长量分别比  相似文献   

10.
灵芝孢子粉食品毒理学安全性评价   总被引:4,自引:0,他引:4  
本文研究了灵芝孢子粉的食品毒理学安全性,结果表明:灵芝孢子粉小鼠经口服LD50〈10g/kg,BW,属无毒级,鼠伤寒沙门氏菌/哺乳动物微粒体酶试验、骨髓微核试验及小表子畸变表明该样品无突变作用、无细胞毒性作用无致突变作用对生殖细胞无致突变作用30天喂养试验结果了大无毒作用剂量大于3.0g/kg,BW/d,可以作保护食品的原料。  相似文献   

11.
通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.  相似文献   

12.
13.
Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m−2 s−1. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to Pfr.  相似文献   

14.
真菌类遗传学分析的知识结构教学   总被引:5,自引:2,他引:3  
罗桂花 《遗传》2002,24(3):349-350
本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.  相似文献   

15.
The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.  相似文献   

16.
17.
龙胆科药用植物化学成分的研究现状   总被引:16,自引:0,他引:16  
龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。  相似文献   

18.
A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.  相似文献   

19.
Summary Anthers were cultured from two sets of seven lines of hexaploid wheat (Triticum aestivum L.) with different cytoplasms, the euplasmic nucleus donors, Siete Cerros 66 and Penjamo 62, as well as their six alloplasmic lines derived from wild relative species of the genera Triticum and Aegilops. Significant cytoplasmic and nuclear effects but no cytoplasmic-nuclear interaction were found for embryogenic anther response, with the best performance of Penjamo 62 in Ae. kotschyi cytoplasm. Plant regeneration was not affected significantly by the cytoplasmic background of the lines cultured. The possible genetic implications of the observed cytoplasmic and nuclear influences on the in vitro haploid induction of wheat are discussed.  相似文献   

20.
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