东亚钳蝎毒素多肽对蜚蠊神经索动作电位的作用

目的 观察两个从国产特有蝎种东亚钳蝎（ＢｍＫ）分离的毒素多肽ＢｍＫⅦ、ＢｍＫⅫ对昆虫中枢神经自发放动作电位的影响。方法 采用蜚蠊中枢神经自发放胞外记录方法。结果ＢｍＫⅦ对蜚蠊中枢神经自发放动作电位有双相作用,先抑制后兴奋,其抑制作用是可逆的。ＢｍＫⅫ对蜚蠊中枢神经自发放动作电位有抑制作用,其抑制作用不是可逆的。结论 提示ＢｍＫⅦ是神经抑制性成分为兴奋性成分的混合物,ＢｍＫⅫ中只有抑制成分。推测：这     

重组蝎毒素基因表达的研究进展

目的介绍重组蝎毒素基因表达的研究进展。方法根据近年来国内外公开发表的有关研究论文 ,综述重组蝎毒素基因表达的研究。结果与结论通过筛选得到的蝎毒素基因或化学合成的编码蝎毒素的基因分别在大肠杆菌、酵母细胞、哺乳动物细胞、昆虫和植物中都有过表达尝试。重组蝎毒素基因表达的关键是如何使有活性的重组蛋白高水平表达     

蝎毒对心血管系统的作用

蝎毒是一种生物毒素 ,因其具有复杂的成分而具有复杂的生理、药理作用。仅就其对内皮细胞功能、血小板功能及微循环、动脉粥样硬化、离子通道、心功能诸方面的影响进行综述。     

Isolation and primary structure of a potent toxin from the venom of the scorpion Centruroides sculpturatus Ewing

A potent toxin has been purified from the venom of the scorpion Centruroides sculpturatus Ewing using the ion-exchange resin CM-Sepharose CL-6B at basic pH. The toxin, designated CsE M₁, comprised 65 amino acid residues and its primary structure was established as: Lys-Glu-Gly-Tyr-Leu-Val-Asn-Ser-Tyr-Thr¹⁰-Gly-Cys-Lys-Tyr-Glu-Cys-Leu-Lys-Leu-Gly²⁰-Asp-Asn-Asp-Tyr-Cys-Leu-Arg-Glu-Cys-Arg³⁰-Gln-Gln-Tyr-Gly-Lys-Ser-Gly-Gly-Tyr-Cys⁴⁰-Tyr-Ala-Phe-Ala-Cys-Trp-Cys-Thr-His-Leu⁵⁰-Tyr-Glu-Gln-Ala-Val-Val-Trp-Pro-Leu-Pro⁶⁰-Asn-Lys-Thr-Cys-Asn. CsE M₁ is the most lethal protein to be identified in C. sculpturatus venom and the LD₅₀ of the toxin, determined by subcutaneous injection into Swiss mice, is 87 μg/kg. CsE M₁ shows strong structural similarity (92% positional identity) to the most potent β-toxin, Css II, from the Mexican scorpion, Centruroides suffusus suffusus but is quite dissimilar to the previously characterized toxins with low potency isolated from C. sculpturarus Ewing.     

Australian scorpion stings: a prospective study of definite stings.

There is little information on scorpion stings in Australia. The aim of this study is to describe the circumstances and clinical effects of stings by Australian scorpions. Cases of scorpion stings were collected prospectively from calls and presentations to Australian poison information centres and emergency departments from February 2000 to April 2002. Only definite scorpion stings where the scorpion was immediately collected and expertly identified were included. There were 95 patients, 33 males and 62 females, with a mean age of 32 (SD 19.5; range 1-71) and 23 children (age<15 years). Three families of scorpions caused all stings: Buthidae (79), Bothruiridae (11, all Cercophonius spp.) and Urodacidae (five, all Urodacus spp.). The majority of stings (76%) were by one genus of scorpion Lychas spp. Seventy one percent of stings occurred between 6pm and 8am and 82 (86%) occurred indoors. Sixty percent of stings occurred on distal limbs. The median duration of effects was 6 h (interquartile range (IQR): 1-24 h). Immediate localised pain occurred in all cases and was severe in 76 cases (80%). Other local effects included red mark/redness (66%), tenderness (35%), numbness (12%) and paraesthesia (11%). Minor systemic effects (nausea, headache and malaise) occurred in 11% of cases. There were no deaths or major systemic envenoming. Less severe effects were observed for the larger Urodacus species, compared to Lychas spp. Scorpion stings in Australia do not appear to cause severe or life-threatening effects, even in children. This differs from other parts of the world, where severe envenoming is reported. The major clinical effect is severe pain, consistent with other scorpion stings. Most stings occurred indoors and at night.     

从自由基角度初探蝎毒及蝎毒多肽对大鼠心肌缺血的作用

目的初步探讨蝎毒(SV)及其主要成分蝎毒多肽(PSV)是否有预防大鼠心肌缺血作用以及是否对自由基造成一定作用。方法采用垂体后叶素构建心肌缺血大鼠模型,用琥珀酸脱氢酶(SDH)染色法制作心肌组织切片进行形态学观察。分光光度法检测血清及心肌组织中超氧化物歧化酶(SOD)和丙二醛(MDA)含量。结果SV组、PSV组在同等条件诱导心肌缺血情况下,其心肌细胞结构得到较好保护。自由基含量在缺血血清及缺血组织中均升高,SV和PSV能降低自由基含量,其中SOD在PSV组的缺血心肌局部甚至高于正常组。结论SV及PSV可能有保护缺血心肌的作用。     

Covalent structure of the insect toxin of the North African scorpion Androctonus australis Hector

The complete covalent structure of the insect toxin purified from the venom of the North-African scorpion Androctonus australis Hector was described. Its amino acid sequence was established by phenylisothiocyanate degradation of several protein derivatives and proteolytic fragments in a liquid protein sequencer using either a “protein” or a “peptide” program. The position of the four disulfide bridges were deduced by analysis of proteolytic peptides before and after performic oxidation, and by partial labeling of the half cystine residues with [¹⁴C]-iodoacetic acid and determining the specific radioactivities of the S-[¹⁴C]-carboxymethylated phenylthiohydantoin cysteines. The sequences of the insect and mammal toxins from scorpions can be aligned with homology with the positions of seven half-cystine residues as registers. The mammal and insect toxins have three disulfide bridges at homologous positions. The fourth bridge is different in that Cys¹² in mammal toxin II is replaced by Cys³⁸ in the insect toxin. It is likely that the position of the disulfide bridges is the same for all scorpion neurotoxins active on mammals. We believe that the shift of one half-cystine residue in the insect toxin may induce a conformational change in the structure of the protein, which, in turn, may partially account for the total specificity of this toxin for insect nervous system.     

全蝎纯化液对实验性动脉血栓形成t-PA、PAI-1的影响

目的观察全蝎纯化液对新西兰白兔颈总动脉血栓形成组织型纤溶酶原激活物(t-PA)、纤溶酶原活化物抑制剂(PAI-1)、血小板计数(Pt)的变化。方法将50只健康新西兰白兔随机分成5组:空白组、模型组、全蝎纯化液大剂量组(20mg/kg)、全蝎纯化液中剂量组(10mg/kg)和全蝎纯化液小剂量组(5mg/kg)。耳缘静脉注射药物(空白组、模型组注射同等体积的生理盐水)后,采用H2O2损伤新西兰白兔颈总动脉制备血栓模型,造模2h后,采血并取血栓,酶联免疫吸附法(ELISA法)检测血浆t-PA、PAI-1的含量。结果与空白组比较,模型组t-PA明显降低,PAI-1明显升高,差异有统计学意义(P<0.01);与模型组相比,全蝎纯化液各剂量组能明显抑制PAI-1活性,增加t-PA活性,差异均有统计学意义(P<0.01),而各组的血小板计数差异无统计学意义(P>0.05)。结论全蝎纯化液各剂量组可明显促进血浆t-PA的分泌,抑制血浆PAI-1活性,提示全蝎纯化液抗血栓作用机制可能与其促纤溶作用有关。     

马氏钳蝎蝎毒对离体豚鼠心脏的作用

本文观察了马氏钳蝎蝎毒(BmKv)对离体豚鼠心脏心肌收缩力和心率的影响。BmKv使心肌收缩力增强,心率减慢。心(?)可阻断其正性肌力作用,阿托品可阻断其负性心率作用,酚妥拉明和戊脉安对BmKv的作用没有影响.表明肾上腺素β受体与BmKv的正性肌力作用有关,而胆硷M受体与其负性心率作用有关,BmKv对离体心脏的作用与肾上腺素α受体、Ca~(++)通道无关。