瑞香素抗血栓作用

瑞香素80 mg/kg iv对大鼠实验性血栓形成有明显的抑制作用,抑制率54%,在试管内当浓度为0.025,0.05及0.1 mg/ml时,可抑制ADP诱导的家兔血小板聚集。iv 80 mg/kg 5 min,对ADP诱导的家兔血小板聚集也有明显的抑制作用。iv 40及80 mg/kg 20 min,皆可使血小板粘附性降低;并能延长小鼠凝血时间。iv 80 mg/kg 5 min,对家兔纤维蛋白原含量,全血粘度及血浆比粘度均无明显影响。     

瑞香素抗血栓作用

瑞香素80 mg/kg iv对大鼠实验性血栓形成有明显的抑制作用,抑制率54%,在试管内当浓度为0.025,0.05及0.1 mg/ml时,可抑制ADP诱导的家兔血小板聚集。iv 80 mg/kg 5 min,对ADP诱导的家兔血小板聚集也有明显的抑制作用。iv 40及80 mg/kg 20 min,皆可使血小板粘附性降低;并能延长小鼠凝血时间。iv 80 mg/kg 5 min,对家兔纤维蛋白原含量,全血粘度及血浆比粘度均无明显影响。     

夏天无总碱对大鼠血小板功能的影响

夏天无总碱(COAMTA)体外实验和体内给药都明显抑制ADP诱导的大鼠血小板聚集,并明显抑制血栓的形成和血小板粘附。COAMTA iv 0.3mg/kg对大鼠实验性血栓形成有明显的抑制作用,抑制率为31.3%。提示上述作用可能是该药治疗脑血管栓塞等疾病有效的机理之一。     

硫代脯氨酸对血栓形成和血小板功能的影响

采用Chandler法测定体外血栓形成,硫代脯氨酸体外浓度为1g/L或iv 25mg/kg可使兔或大鼠Chandler环中形成的血栓长度缩短、血栓湿重和干重减轻;采用旋转法测定血小板粘附性,硫代脯氨酸浓度为1g/L时使兔血小板粘附性降低;采用比浊法测定血小板聚集性,硫代脯氨酸体外浓度为1g/L PRP或iv50mg/kg均明显抑制ADP诱导的兔血小板聚集。     

山茱萸环烯醚萜苷对家兔、大鼠血小板聚集及出血时间的影响

目的：研究山茱萸环烯醚萜苷（CIG）对血小板聚集和出血时间的影响。方法：应用比浊法测定家兔（体外实验）及血瘀模型大鼠（体内实验）的血小板聚集率;断尾法观察大鼠出血时间。采用肾上腺素加冰水刺激法制备血瘀大鼠模型。结果：在体外实验中,CIG（0.75～3 mg/mL）能明显抑制二磷酸腺苷（ADP）或花生四烯酸（AA）诱导的家兔血小板聚集（P〈0.05,P〈0.01）,对血小板活化因子（PAF）诱导的血小板聚集无显著影响,但更大剂量（6～12 mg/mL）能抑制PAF诱导的血小板聚集（P〈0.01）。在体内实验中,CIG大剂量（180 mg/kg）灌胃给药能显著抑制ADP诱导的血瘀模型大鼠血小板聚集（P〈0.01）,延长正常大鼠的出血时间（P〈0.05）。结论：山茱萸环烯醚萜苷具有抗血小板聚集作用,大剂量能够延长出血时间。     

哒嗪酮类新化合物9612的抗血小板聚集作用

研究了新型哒嗪酮类化合物 96 12对家兔和大鼠血小板聚集的影响 .结果发现 ,96 12在体外能明显抑制花生四烯酸 (AA) ,腺苷二磷酸 (ADP)和凝血酶 (thrombin)诱导的家兔血小板聚集 ,其IC50 分别为 3 2 0 ,9 44和 7 10 μmol/L .96 12 .灌胃给药 (ig) ,能显著抑制AA和ADP诱导的大鼠血小板聚集 ,其作用与同等剂量 (15 0mg/kg)的阿斯匹林 (ASA)相比无明显差异 (P >0 0 5 ) .     

咪苯嗪酮对血小板聚集、血栓形成和血小板环磷酸腺苷含量的影响

本文观察了新型强心剂咪苯嗪酮(Cl-914)对血小板聚集、血栓形成和血小板cAMP含量的影响。用比浊法测定Cl-914体外抑制AA,ADP和胶原诱导兔血小板聚集的IC_(50),分别为2.6,8.9和15.8μM;大鼠iv Cl-914 1.25mg/kg能抑制实验性血栓形成,20 mg/kg能抑制上述三种诱导剂引起的血小板聚集。在体外,用竞争性蛋白结合法测定,CI-914可使洗涤兔血小板cAMP含量明显升高。CI-914能以剂量依赖方式协同PGE_1抑制血小板聚集和升高血小板cAMP的含量。提示CI-914升高血小板cAMP含量可能是其抑制血小板聚集和抗血栓形成的主要机理。     

单甘酯对血小板功能及纤维蛋白原含量的影响

目的 :研究单甘酯对血小板聚集、粘附功能及出血时间和纤维蛋白原含量的影响。方法 :比浊法观察血小板聚集功能 ,玻瓶法观察血小板粘附功能 ,小鼠剪尾法观察出血时间 ,比色法测定纤维蛋白原含量。结果 :单甘酯 2 5、5 0mg/kg对血小板粘附有明显抑制作用 ,2 5、5 0、10 0mg/kg(iv)能明显抑制胶原和花生四烯酸诱导的血小板聚集 ,对ADP诱导的血小板聚集无抑制作用 ;40、80mg/kg(ip)可明显延长小鼠尾出血时间 ;2 5mg/kg(iv)即可降低大鼠血浆纤维蛋白原含量。结论 :单甘酯有明显的抑制血小板功能和降低血浆蛋白原含量的作用。     

绞股蓝提取物对家兔血小板聚集和花生四烯酸代谢的影响

绞股蓝提取物(0.25～2g/L,终浓度)在体外明显抑制花生四烯酸诱导的家兔血小板聚集和血栓素B_2(TXB_2)释放,剂量与效应相关;该药抑制血小板释放TXB_2的ID_(50)为0.28g/L。体内实验静脉注射绞股蓝提取物35mg/kg后10和20min时,血小板聚集明显抑制,10～40min期间血小板释放TXB_2量明显减少,以10和20min时最著。该药(0.25～4g/L)在体外对家兔胸主动脉释放6-酮-PGF_(1α)无影响。实验结果表明,绞股蓝提取物对降低血栓素A_2/前列环素比值有较好作用。     

2-萘-3-(3,4-二甲氧基)苯丙烯酸抗血小板聚集作用及其机理

研究发现,NMPA在体外可抑制花生四烯酸、胶原及凝血酶诱导的家兔血小板聚集,IC_(50)分别为189±9,105±11.0,49.8±16.6μM。小鼠ig NMPA(25mg/kg)后,以ADP诱导的血小板聚集明显受到抑制。大鼠ig NMPA后(52mg/kg一次或10mg/(kg·d)连续7d,出血时间延长、胶原诱导的血小板聚集率下降、丙二醛生成减少、但对动脉壁PGI_2样物质影响较小。说明MNPA的作用机理可能在于改变体内TXA_2/PGI_2比值,而达到抑制血小板聚集的效应。     

人参皂甙对血小板聚集性、cAMP和cGMP含量的影响

本文报告了人参皂甙对家兔血小板聚集性,cAMP和cGMP含量的影响。结果表明,人参皂甙在体内外均抑制由花生四烯酸、ADP和凝血酶诱导的血小板聚集。同时,人参皂甙明显升高血小板中cAMP含量,但是不影响血小板中cGMP含量。提示人参皂甙对血小板聚集的抑制作用与其升高血小板中cAMP含量有关。     

虎杖晶Ⅳ号对家兔血小板聚集的影响

Polydatin is 3,4′, 5-trihydroxystilbene-3-β-mono-D-glucoside isolated from Polygonum cuspidatum Sieb et Zucc. The actions of polydatin 0.6, 2.6 and 10.4 μg/ml in vitro and 5 mg/kg in vivo on platelet aggregation were studied in rabbits. Polydatin was shown to inhibit ADP, arachidonic acid, Ca²⁺ and clonidine-induced platelet aggregation significantly. In vitro, the rates of inhibition were 18～36% (ADP-induced), 26～58% (arachidonic acid-induced) and 42～64% (Ca²⁺-induced). However, the inhibition of thrombin-induced aggregation was not statistically significant. In in vivo experiments, 5, 30 and 60 min after iv polydatin, the rates of inhibition were 52～63% (ADP-induced), 59～76% (arachidonic acidinduced) and 10～16% (Ca²⁺-induced) respectively.     

Effect of the new antimigraine drug serotonin receptor antagonist tropoxin on platelet aggregation

The effect of the new antimigraine drug tropoxin - the serotonin receptor (5-HT2) antagonist - on the human platelet aggregation in vitro induced by ADP (1 x 10(-5) M) and epinephrine (2.5 x 10(-6) M) was studied. Tropoxin reliably inhibited the ADP-induced platelet aggregation in a concentration range of 0.01 - 7 mg/ml. A significant inhibition effect with respect to the epinephrine-induced platelet aggregation was observed in a drug concentration range of 2 - 7 mg/ml, although a reliable antiaggregant activity was also observed below 2 mg/ml. A bolus administration of tropoxin (10 mg/kg) in rabbits decreased the ADP-induced platelet aggregation ex vivo by a factor of 1.2 - 1.4. The effect appeared 45 min after treatment and was observed during subsequent 30 min.     

抗人血小板膜糖蛋白Ⅲa单克隆抗体抑制兔血栓形成的实验研究

目的　评价抗人血小板膜糖蛋白Ⅲa单克隆抗体SZ21抑制兔血栓形成的能力。方法不同浓度的SZ21（0、10及20μg／ml）分别加入兔富血小板血浆（PRP）中,进行二磷酸腺苷（ADP）诱导的兔血小板聚集试验;体内注射SZ21（1.5mg／kg）,注射前及注射后5、30及60分钟时制备兔PRP,分别进行聚集试验;用颈动静脉旁路血栓模型研究SZ21对兔血栓形成的作用,20只新西兰兔随机分成4组,体内注射SZ21,剂量为A组0.1mg／kg,B组0.4mg／kg,C组0.75mg／kg,D为对照组（SZ391mg／kg）,然后测定血栓重量。结果　体外20μg／ml的SZ21对兔血小板抑制率为80％;SZ21体内注射60分钟时完全抑制血小板聚集功能;血栓模型分组试验,各组平均栓重为A组31mg,B组21mg,C组20.2mg,D组31mg,B、C组与对照组间有明显统计学差异（P＜0.01）。结论　单克隆抗体SZ21能有效抑制兔动静脉旁路血栓形成。     

The suppressive effect of pyrrole-2-carboxylic acid on platelet aggregation

In the course of a search for novel antibiotics, an antiplatelet substance was isolated from the fermentation broth of Streptomyces sp. No. 82-85. Thereafter, the active substance was identified as pyrrole-2-carboxylic acid (P2C) by structural studies. The effects of P2C on adenosine diphosphate (ADP)-, arachidonic acid-, collagen- or tumor cell-induced platelet aggregation were examined in vitro and ex vivo. In in vitro studies, P2C (25-100 micrograms/ml) suppressed the aggregation of platelets of normal Wistar rats. The intraperitoneal administration of P2C (200 mg/kg) to rats and rabbits suppressed platelet aggregation induced by ADP, arachidonic acid and collagen when examined for 0.5-3 hours after administration. The agent also suppressed platelet aggregation induced by both mouse syngenic tumors, Meth-A fibrosarcoma and IMC carcinoma in vitro.     

Can we use adenosine diphosphate (ADP) to study "aspirin resistance"? The Janus faces of ADP-triggered platelet aggregation

There is a growing number of contradictory reports indicating that adenosine diphosphate (ADP) can be a useful agonist in monitoring of the antiplatelet action of acetylsalicylic acid (ASA) in humans and animals. In the current study, we aimed to determine the conditions for using ADP to trigger platelet aggregation in order to detect ASA-mediated inhibition of rat platelet reactivity. Initially, we examined the usefulness of different ADP concentrations (0.25, 0.5, 1, 5 and 10 muM) in detecting the in vitro ASA mediated platelet inhibition using whole blood aggregometry, as well as we monitored the role of ADP in generation of thromboxane A(2) (TXA(2)). To study ex vivo ASA inhibitory potential on platelet aggregation induced by a range of ADP concentrations, animals were subjected to one or 10-day ASA administration at the dose of 50 mg/kg. Our experiment shows that ADP in a concentration-dependent manner induces TXA(2) generation in the whole blood with hirudin as an anticoagulant. However, in vitro and ex vivo examination of ASA inhibitory potential on platelet aggregation revealed that irrespectively of administration regimen, ASA failed to block platelet aggregation induced byADPat the concentrations higher than 0.5 muM. Our findings suggest that the mechanism of ADP-induced platelet aggregation depends on agonist concentration. It appears that only low ADP concentrations (up to 0.5 muM) induce TXA(2)-dependent rat platelet aggregation. Therefore, ADP could be considered a useful platelet agonist for monitoring of ASA-mediated platelet inhibition only if used at much lower concentrations than those commonly employed.