尖吻蝮蛇毒小分子多肽的分离及抗血小板聚集作用

目的从尖吻蝮蛇毒中分离纯化一种抗血小板聚集小分子多肽,研究其理化性质以及对ADP、胶原、凝血酶诱导的血小板聚集反应的影响。方法经SephadexG-75凝胶过滤,超滤,DEAE-SepharoseCL-6B离子交换层析法分离纯化蛇毒组分,采用高效液相鉴定纯度,用SDS-凝胶电泳(SDS-PAGE)测定其分子量,用比浊法测定其抗血小板聚集活性。结果从尖吻蝮蛇毒中分离相对分子质量约为7862u等电点为4.29的组分,该组分能抑制由ADP、胶原、凝血酶诱导的血小板聚集并成剂量依赖性。结论此法成功地从尖吻蝮蛇毒中纯化出抗血小板聚集组分。该组分与去整合素比较相似,可能属于去整合素家族。     

原矛头蝮蛇毒及其组分对凝血功能的影响

目的研究原矛头蝮蛇毒(PMV)及其组分作用于血液循环系统的部分生物学活性,进一步探讨其毒性机制。方法采用Sephadex G-75凝胶层析方法分离不同分子质量范围的蛋白组分FⅠ,FⅡ和FⅢ。贫血小板血浆调节富血小板血浆使血小板为3×1011L-1,血小板悬液分别与PMV,FⅠ,FⅡ和FⅢ0.03 g·L-1预孵育5 min,血小板聚集仪测定PMV及其组分诱导血小板聚集活性;PMV,FⅠ,FⅡ和FⅢ0.05 g·L-1分别与纤溶酶原0.1 U·L-1预孵育10 min,采用单一时间点测定和酶动力学测定PMV及其组分酶切发色底物S-2251的作用;将大鼠血浆与PMV,FⅠ,FⅡ和FⅢ1.0 g·L-1分别孵育5和30 min,测定凝血酶时间(TT)、活化部分凝血活酶时间(APTT)、凝血酶原时间(PT)和纤维蛋白原(FIB)水平;PMV,FⅠ,FⅡ和FⅢ10,50和250 mg·L-1处理微血管内皮细胞24 h,倒置相差显微镜观察细胞形态,MTT法检测细胞存活;PMV,FⅠ,FⅡ和FⅢ0.1 g·L-1与含卵磷脂和不含卵磷脂的豚鼠红细胞悬液分别孵育不同时间,计算溶血率。结果与对照组相比,PMV和高分子质量蛋白组分FⅠ(>71 ku)诱导血小板聚集率显著升高〔(61.0±5.8)%和(56.9±5.9)%vs(12.4±4.1)%〕(P<0.01)。酶切发色底物S-2251结果显示,PMV与中分子质量组分FⅡ(18~37 ku)具有酶切发色底物的作用(P<0.01)。PMV和FⅠ可引起血浆凝固。与对照组相比,FⅡ组分和低分子质量蛋白组分FⅢ(<10 ku)明显使TT,APTT和PT的时间延长(P<0.01)。PMV,FⅠ及FⅡ导致内皮细胞解离悬浮,与对照组相比,细胞存活率下降,分别为(56.8±3.6)%,(71.6±3.8)%和(58.2±5.5)%。在无卵磷脂条件下,PMV和FⅡ可缓慢地引起红细胞轻度溶血;在卵磷脂参与下,PMV和FⅡ引起豚鼠红细胞急剧溶血,与正常对照组相比,在0.5 min内溶血率从(17.7±1.0)%分别升高至(81.0±4.0)%和(81.0±1.0)%(P<0.01)。结论 PMV在体外表现出多方面的血循毒性质的活性,不同分子质量蛋白组分活性机制及作用不同。     

原矛头蝮蛇毒的抗凝作用

目的 研究原矛头蝮蛇毒(PMV)对血液系统的作用。方法 将PMV 0.2 mg·kg^-1一次性尾静脉注射给予SD大鼠。注射后0.5, 1, 3, 6和24 h分别取下腔静脉血,制备抗凝全血、抗凝血浆和富血小板血浆(PRP)。利用血细胞计数板对抗凝全血和PRP进行血小板计数;将抗凝血浆用生理盐水稀释5倍,在412 nm测定血红蛋白含量;采用凝血酶时间(TT)、凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)和纤维蛋白原(FIB)含量测定试剂盒分别测定抗凝血浆的TT, APTT, PT和FIB含量;用发色底物法测定抗凝血浆酶切发色底物S-2251的活性。给昆明小鼠一次性尾静脉注射PMV 0.28 mg·kg^-1,在0.5, 1, 3, 6和24 h测定尾部出血时间。结果 给予PMV 0.2 mg·kg^-1 30 min大鼠抗凝全血血小板计数减少至正常对照组的1/3(P<0.01),PRP中血小板计数减少至正常对照组的1/20(P<0.01),抗凝血浆血红蛋白含量增加约6倍(P<0.01);给予PMV 6 h APTT明显延长(P<0.05),3和6 h TT明显延长(P<0.01),1和3 h PT明显缩短(P<0.01);FIB含量和抗凝血浆酶切发色底物S-2251的活性无明显变化。给予小鼠PMV 0.28 mg·kg^-1 30 min小鼠尾部出血时间达(2341±742)s,较正常对照组小鼠(81±11)s明显延长(P<0.01),1 h逐渐缩短(P<0.01),24 h仍未恢复至正常水平(P<0.05)。结论 PMV具有明显的抗凝作用。     

福建尖吻蝮蛇毒类凝酶对家兔血小板数量及血栓素B2的影响

传统观念认为蛇毒只具有抗凝血作用,但近年来进一步研究发现,蛇毒中提纯出的一种凝固蛋白(蛇毒类凝酶)在大剂量时具有抗凝血作用,作为抗凝药用于溶栓治疗;小剂量具有止血作用,作为止血药。由于蛇毒的产地、种类不同,作用也不尽相同,     

蝮蛇毒蛋白C激活物抗凝机制的研究

目的研究蝮蛇毒纯化蛋白C激活物(PCA)的抗凝机制.方法测定PCA对正常人混浆KPTT、PT、TT的影响;对白兔的KPTT、PT、TT和Fgn的影响.结果PCA在0.1 mg@L1时对正常人混浆KPTT可明显延长,但PT和TT不受影响,当它的浓度增到200mg@L,PT也可延长,但TT依然无明显变化;PCA可明显延长白兔的KPTT.结论PCA在低浓度时优先抑制凝血系统第一阶段内凝途径,在高浓度时也妨碍外凝途径或共同途径,具有体内抗凝作用.     

蝮蛇抗栓酶对体外血小板聚集的影响

本文比较了不同的浓度蝮蛇抗栓酶(svate)对人血小板聚集的影响。结果表明,不同浓度蝮蛇抗栓酶对试管内血小板聚集均有明显抑制作用,其抑制作用与浓度呈正比。     

蝮蛇抗栓酶对脑梗塞患者血小板数量的影响与临床关系

蝮蛇抗栓酶对脑梗塞患者血小板数量的影响与临床关系山西医学院第一附属医院（０３０００１）张生林，刘玉玺，马晋萍山西省汽车制造厂贾殿华蝮蛇抗栓酶治疗急性脑梗塞颇有疗效［１，２］，但在用药过程中患者有可能会出现疲乏、肢体无力等症状。我们观察到这些症状和血小板数量减少有关，现将其结果报告如下。临床资料２２例入院的急性脑梗塞患者，全部作了ＣＴ扫描。其中男性１５例，女性７例；年龄为１６～７０岁。入院后行一般常规神经系统检查，用专门表格记录用药前后体征、症状与血小板数量的变化。药前行二次血小板计数，取其均值作为对照组。药后分别于３、６、９天及两周时取耳垂毛细血管测血小板数。若患者在用药过程中出现皮疹、乏力时则每天测血小板数。当血小板下降到６０～８０×１０９／Ｌ时或疲乏、肢体无力明显时即停药，待症状好转或消失测血小板数，行第二个疗程治疗。蝮蛇抗栓酶为沈阳第一制药厂生产。开始用量为０．５个酶活力单位，第一个疗程每隔３天增力０．２５个单位，最大量达１．７５个单位。结果一、应用蝮蛇抗栓酶后不同时期内血小板数量的变化见表１。二、血小板变化与临床症状与体征间关系。用蝮蛇抗栓酶后，部分患者会出现搔痒、皮肤出血点、疲乏、肢体乏力和不适等     

蝮蛇毒纤溶酶的分离纯化及性质研究

目的 :寻找一种分离纯化蝮蛇毒纤溶酶的工艺并研究其理化性质。方法 :采用DEAE SepharoseCL 6B和HeparinCL 6B层析方法 ,从蝮蛇毒中分离纯化纤溶酶。结果 :蝮蛇毒纤溶酶经HPLC为单一峰 ,等电聚焦电泳为一条带 ,其等电点为 4.5 5 ,经SDS 聚丙烯酰胺凝胶电泳测得分子量为 2 9.4kD。该酶对热不稳定 ,在 pH6～ 9时稳定 ,氨基酸组成分析表明含酸性氨基酸较多。结论 :用此工艺可制得高纯度的蝮蛇毒纤溶酶。     

江浙蝮蛇毒镇痛组分对吗啡依赖大鼠尾状核神经肽的调控作用

目的:研究江浙蝮蛇毒镇痛C4组分对大鼠尾状核中神经肽水平的调控作用.方法:应用微透析技术,探针定位于大鼠尾状体,以人工脑脊液透析,HPLC检测亮氨酸脑啡肽、β-内啡肽和P物质的含量,动态监测其变化.结果:在吗啡依赖大鼠给予C4组分后,尾状核亮氨酸脑啡肽含量显著增高,为可乐定组的1.5倍,并持续作用8h以上,而β-内啡肽和P物质含量变化较小.结论:C4组分主要作用于亮氨酸脑啡肽,通过提高其含量发挥镇痛作用.     

江浙蝮蛇毒镇痛组分的分离纯化及其理化性质

目的　分离筛选江浙蝮蛇毒中主要镇痛组分 ,研究其分子量、等电点、纯度、氨基酸序列、稳定性等理化性质 ,以及镇痛作用、机体耐受性和依赖性等药理学性质。方法　采用离子交换和分子筛 ,以柱层析法分离蛇毒组分。用生化测定方法 ,测定其理化性质。用热板法和醋酸扭体法等确定最佳镇痛组分 ,并用纳洛酮催促和自然戒断实验、耐受性实验考察其依赖性和耐受性。结果　分离获得 14个蛋白组分 ,经ED50 /LD50 筛选出最佳镇痛组分C4 ,鉴定结果表明纯度为电泳纯 ,HPLC相对纯度为 92 .16 % ,分子量 16 .6ku ,等电点 8.8,氨基酸序列与磷脂酶A2 同源 ,为一种新的镇痛蛋白 ,并获得其紫外吸收特征峰、镇痛耐受和依赖性等性质。结论　C4组分具有显著的镇痛效果 ,未发现耐受性和依赖性 ,值得进一步研究开发。     

Pharmacokinetics of thrombin-like enzyme from venom of Agkistrodon halys ussuriensis Emelianov determined by ELISA in the rat.

A thrombin-like enzyme (TLE) was separated and purified from the venom of a northeast Chinese snake Agkistrodon halys ussuriensis Emelianov. Experiments were performed in rats to determine the pharmacokinetic parameters following an intravenous (i.v.) or a subcutaneous (s.c.) injection of the thrombin-like enzyme. The plasma levels of TLE were estimated by enzyme-linked immunosorbent assay. The method exhibited high reproducibility and accuracy in correlating optical densities with TLE concentrations (0.2–30 ng ml⁻¹, r=0.99). The plasma concentration-time course after i.v. administration of 50 μg kg⁻¹ TLE was well fitted by a two-compartment open model. The half-life of the -phase was 18.0±3.2 min, and that of the β-phase 3.9±0.7 h. The apparent volume of distribution was 1.8±0.5 l kg⁻¹, and clearance was 5.4±0.5 ml min⁻¹ kg⁻¹. When the TLE was injected s.c. at a dose of 0.75 mg kg⁻¹, the changes in plasma concentration were best described by a two-compartment model with a first-order absorption. The maximal plasma level of 51±2.7 ng ml⁻¹ was reached at 5.2±0.5 h. The absorption rate constant was 0.3±0.03 h⁻¹. The area under the plasma concentration-time curve (AUC) was 2.8±0.8 μg h⁻¹ ml⁻¹.     

蛇毒降纤酶多克隆抗体的制备及其某些性质

为制备长白山白眉蝮蛇蛇毒降纤酶的多克隆抗体 ,以期获得酶免疫测定所需的反应试剂 ,供药剂学的研究应用。经免疫兔获得高效价的抗长白山白眉蝮蛇蛇毒降纤酶的抗血清 ,以环状沉淀反应、琼脂免疫双扩散 ,以及酶联免疫吸附法 ,验证了产生的抗体。免疫双扩散及ELISA测定的结果表明 ,长白山白眉蝮蛇蛇毒降纤酶与日本克栓酶有着不同的抗原决定簇结构。 3只兔的抗血清以 1∶7 2万的倍数稀释时 ,其在ELISA测定中的光密度 (OD4 90nm)仍比空白对照高出 0 2以上 ,具有较高效价 ;该抗体与精制蝮蛇抗栓酶有一定的交叉反应 (比率为 0 0 2 4) ,与江浙蝮蛇蛇毒粗品及日本克栓酶间的交叉反应微小 (比率小于 0 0 0 1) ,具有较好特异性     

Primary structure of a thrombin-like serine protease, kangshuanmei, from the venom of Agkistrodon halys brevicaudus stejneger.

The complete amino acid sequence of the thrombin-like serine protease, named kangshuanmei, isolated from the venom of a Chinese snake Agkistrodon halys brevicaudus stejneger, was determined by Edman degradation. The serine protease was composed of 236 amino acid residues and conserved the catalytic triad as His43, Asp88 and Ser182. The protease had four sites of asparagine-linked glycosylation at 81, 99, 148 and 229, and contained fucose, N-acetylglucosamin, galactose, mannose and N-acetylneuraminic acid. The amino acid sequence exhibited considerable similarities with other thrombin-like proteases isolated from the snake venoms of the Viperidae family. However, the enzymatic characteristics of kangshuanmei distinct from that of thrombin and the other protease from the venom of Viperidae family may be derived from the structural difference of the sequence in the functional regions, especially corresponding to thrombin exosite 1, 2 and hydrophobic pocket.     

Hemorrhagic activity and mechanism of FⅡa′a fibrinolytic enzyme from Agkistrodon acutus venom

AIM: To study the local hemorrhagic activity of a fibrinolytic enzyme (FⅡa) from Agkistrodon acutus venom and its mechanism. METHODS: The local hemorrhagic activity was determined by subcutaneous injection on the back of mouse. The effects of FⅡa on factor X, prothrombin, gelatin, and collagen were visualized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Platelet aggregation assays were performed in rat platelet-rich plasma (PRP). Human umbilical vein endothelial cells (HUVEC) were cultured and passaged in complete M 199 medium. Cell viability and nuclear morphology change were determined by fluorescein diacetate (FDA) staining and Hoechst 33258 staining, respectively. RESULTS: The minimum hemorrhagic dose (MHD) of FⅡa was 89 μg.In vitro, FⅡa (0.25 g/L) degraded factor X, prothrombin, collagen, and gelatin, and dose-dependently (0.25, 0.50,0.75, and 1.00 g/L) inhibited the platelet aggregation induced by ADP in rat PRP. When HUVEC in culture treated with FⅡa, HUVEC showed detachment in a dose-dependent manner, but no apoptosis sign was observed.CONCLUSION: FⅡa had local hemorrhagic activity, and the mechanism was related to the degradation of factor X,prothrombin, gelatin, and collagen, the inhibition of ADP-induced platelet aggregation, and inducement of HUVEC detachment.     

Purification and characterization of a new platelet aggregation inhibitor with dissociative effect on ADP-induced platelet aggregation, from the venom of Protobothrops elegans (Sakishima-habu)

A platelet aggregation inhibitor, named snake venom platelet aggregation dissociator (SV-PAD)-1, with a dissociative reaction of ADP-induced platelet aggregation, was purified from the venom of Protobothrops elegans (Sakishima-habu) by gel-filtration employing Sephadex G-100, and ion-exchange chromatographies using DEAE-Sepharose Fast Flow, CM-Sepharose Fast Flow, and Mono S. By this procedure, about 1.5 mg of purified protein was obtained from 1.0 g of P. elegans venom. The purified protein showed a single protein band and the molecular weight was about 110 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under reducing conditions. The pI of purified protein showed four-bands of 7.7, 7.8, 7.95, and 8.15. This protein strongly inhibited ADP-induced platelet aggregation in rabbit platelet-rich plasma (PRP), and its IC₅₀ was about 58 nM. It inhibited ristocetin-induced platelet aggregation in rabbit PRP (IC₅₀: 100 nM), but hardly blocked collagen-induced platelet aggregation. This protein promptly dissociated platelet aggregation in rabbit PRP stimulated by high-concentration ADP.