6-(αα-二苯基乙酰哌嗪基苯基)-4,5-二氢-5-甲基-3(2H)-哒嗪酮对兔血小板聚集及TXB_2,cAMP的影响

6-(αα-二苯基乙酰哌嗪基苯基)-4,5-二氢-5-甲基-3(2H)-哒嗪酮(简称DMDP)是我院新合成的哒嗪酮的衍生物。DMDP可以显著抑制由花生四烯酸(AA(?),ADP和血小板活化因子(PAF)诱导的免血小板聚集,其IC_(50)分别为1.12±0.1.4.19±0.5和2.97±0.1μmol/L。实验还表明DMDP在1～500 μmol/L浓度范围内呈剂量依赖性地抑制兔血小板内血栓素B_2含量,但升高兔血小板内环腺苷酸水平,这可能是其抑制血小板聚集的作用机理之一。     

亚硒酸钠在兔体内的药代动力学

给家兔单次iv或ig Na_2SeO_3 2.0mg/kg,iv血药-时曲线符合线性三室开放模型,药代动力学参数为t_(3/2)a 0.16±0.08d,t_(1/2)β9.93±2.52d,t_(1/2)π0.13±0.08 h,ig血药-时曲线符合二室开放模型,药代动力学参数t_(1/2)(Ka)2.69±0.56h,t_(1/2)a 0.96±0.45d,t_(1/2) β9.31±3.36 d。多次给硒时,每7d,14d igNa_2SeO_3 2.0mg/kg,每10d iv Na_2SeO_3 1.5mg/kg各组达到90％以上稳态血药水平的时间分别为35d,45d和30d。     

6-(αα-二苯基乙酰哌嗪基苯基)-4,5-二氢-5-甲基-3(2H)-哒嗪酮对兔血小板聚集及TXB2,cAMP的影响

6-(αα-二苯基乙酰哌嗪基苯基)-4,5-二氢-5-甲基-3(2H)-哒嗪酮(简称DMDP)是我院新合成的哒嗪酮的衍生物。DMDP可以显著抑制由花生四烯酸(AA(?),ADP和血小板活化因子(PAF)诱导的免血小板聚集,其IC₅₀分别为1.12±0.1.4.19±0.5和2.97±0.1μmol/L。实验还表明DMDP在1～500 μmol/L浓度范围内呈剂量依赖性地抑制兔血小板内血栓素B₂含量,但升高兔血小板内环腺苷酸水平,这可能是其抑制血小板聚集的作用机理之一。     

1-(2,6-二甲基苯氧基)-2-(3,4-二甲氧基苯乙胺基)丙烷盐酸盐对实验性高血压大鼠的降压作用

DDPH 3～10 mg/kg iv降低DOCA—盐型及自发性高血压(SH)大鼠的MAP及HR;50,100mg/kg ig降低清醒正常血压及SH大鼠MAP及HR·心率减慢较降压作用持续时间短。DDPH(10,100μmol/L)对犬乳头状肌收缩力及静息30 s后第一次收缩(PRC_(30))有抑制作用。小鼠ig DDPH的LD_(50)为640 mg/kg,95％可信限为567～713mg/kg。麻醉大鼠静脉恒速灌注DDPH的致死量为47±SD 4 mg/kg。表明DDPH对实验性高血压大鼠有降压作用,并对心肌收缩力及肌浆网Ca~(2+)的释放有轻度抑制作用。     

当归及其成分阿魏酸对大鼠血小板聚集和5-HT释放的影响

本文报告当归及其成分阿魏酸对大鼠血小板聚集性和5-HT释放反应的影响。结果表明,当归水剂在试管内当浓度为200～500mg/ml,阿魏酸0.4～0.6mg/ml时抑制ADP和胶原诱导的大鼠血小板聚集。静脉注射当归20g/kg 5分钟后对ADP和胶原诱导的大鼠血小板聚集有明显的抑制作用。阿魏酸钠0.2g/kg和0.1g/kg静脉注射时分别抑制ADP和胶原诱导的大鼠血小板聚集。用³H-5HT标记血小板,观察血小板聚集和释放反应的关系。当归水剂500mg/ml和阿魏酸钠1～2mg/ml对凝血酶诱导的血小板聚集有明显抑制作用,同时也抑制³H-5HT从血小板中释放。     

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。     

钩藤碱对血小板聚集和血栓形成的影响

钩藤碱(Rhy)明显抑制AA,胶原及ADP诱导的大鼠血小板聚集。Rhy不影响血小利用外源性AA合成TXA_2,但抑制胶原诱导的TXA_2生成;在抗血小板聚集有效剂量时,对PGI_2的生成无影响。Rhy有显著降低血栓形成诱导剂ADP及胶原加肾上腺素静脉注射所致小鼠死亡率。     

氯吡格雷对二磷酸腺苷诱导的血小板聚集的影响

目的 :探讨氯吡格雷对血小板聚集率的影响。方法 :血小板聚集率增高病人 2 4例 ,男性 1 4例 ,女性 1 0例 ,年龄 (5 9±s 1 0 )a。给予氯吡格雷5 0mg ,po,qd×4wk。在服药后 8d,4wk后用光学法测定血小板聚集率 (ADP诱导法 ) ,Duke法测定出、凝血时间 ,凝血因子Ⅰ及血小板计数。结果 :高血小板聚集率的病人使用氯吡格雷后血小板聚集率明显下降 ,治疗后 8d,4wk分别下降 (3 1±2 5 ) % ,(3 2± 2 1 ) % ,(P <0 .0 1 )。但出、凝血时间 ,血小板计数及凝血因子Ⅰ含量在使用氯吡格雷后无明显变化。结论 :氯吡格雷可有效拮抗ADP诱导的血小板聚集作用     

舒脑欣滴丸对寒凝气滞血瘀证大鼠血小板聚集和血液流变学指标的影响

目的探讨舒脑欣滴丸对急性血瘀模型大鼠血小板聚集和血液流变学指标的影响。方法选取70只Wistar大鼠,随机分为对照组,模型组,舒脑欣滴丸13、26、52 mg/kg组,阳性药脑心通胶囊(15 mg/kg)、阿司匹林肠溶片(15 mg/kg)和藻酸双脂钠片(90 mg/kg)组,连续ig给药7 d,1次/d,末次给药后1 h,采用sc 0.1%肾上腺素加在冰水中游泳的方法,制备大鼠急性血瘀模型,观察舒脑欣滴丸对不同血小板聚集诱导剂二磷酸腺苷(ADP)、花生四烯酸(AA)和胶原(CG)引起的大鼠血小板聚集影响;通过检测血液流变学指标、凝血功能评价舒脑欣滴丸对血瘀模型大鼠的作用。结果舒脑欣滴丸对3种不同血小板聚集诱导剂引起的血小板聚集均有不同程度的抑制作用,可显著降低全血黏度,延长血瘀模型大鼠凝血酶原时间(PT)、活化部分凝血活酶时间(APTT)。结论舒脑欣滴丸13、26、52 mg/kg具有明显活血化瘀作用,能降低血液黏度,抑制多种诱导剂引起的血小板聚集,具有一定抗凝活性。     

西洋参茎叶总皂甙的药理、毒理研究

西洋参茎叶中提取的总皂甙,ip25和50mg/kg,可使小鼠自发活动次数由对照组的64.4±18.4减少为16.8±4.4和4.3±2.5(p<0.01);ig425和850mg/kg由73.3±19.7减少为30.8±14.6和18.4±4.8(p<0.01);ig850mg/kg能使阈下剂量的戊巴比妥钠催眠时间持续30.0±0.0min(p<0.01);ip20mg/kg和ig850mg/kg小鼠耐缺氧平均存活时间由对照组的37.6±8.2和37.5±7.7min延长为48.6±8.6和68.3±21.8min(p<0.01);ig30和60mg/kg,可对抗环磷酰胺引起的WBC减少。ip和ig给药,LD_(50)分别为204±SE2.6mg/kg和8511±SE1061mg/kg;长期毒性实验表明,动物体重、脏器重量、WBC、Hcmo各组间无显著差异,GPT、ZTT及TTT均在正常值范围,动物脏器经病理组织学检查属基本正常。     

香草酸抗血小板聚集作用的体内外研究

目的香草酸是一种酚酸类化合物,具有抗氧化、抗炎等药理作用,其抗血栓作用尚未有报道。本实验室前期通过筛选发现香草酸具有良好的抗血小板聚集作用,因此本研究通过体内外实验对香草酸抗血小板聚集的作用进行系统评价。方法采用花生四烯酸(arachidonic acid,AA)、二磷酸腺苷(adenosine diphosphate,ADP)、凝血酶(thrombin,THR)诱导体内外血小板聚集模型,结合凝血四项检测评价香草酸抗血小板聚集及抗血栓的作用。结果体外实验中,香草酸对ADP和AA诱导的血小板聚集具有显著抑制作用,并剂量依赖性抑制ADP诱导的血小板聚集;体内试验中,香草酸(10、30和100 mg/kg)能够剂量依赖性抑制ADP和AA诱导的血小板聚集;同时,香草酸(100 mg/kg)能显著降低纤维蛋白原、增加凝血酶原时间,对活化部分凝血活酶时间和血浆凝血酶时间无明显影响。结论本研究首次发现香草酸对ADP和AA诱导的血小板聚集具有抑制作用,为研发具有自主知识产权的抗血小板聚集药物提供了实验依据。     

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 ) .     

奥昔麻黄碱对凝血酶诱导家兔血小板聚集和丙二醛生成的影响

Oxy明显地抑制凝血酶诱导洗涤的兔血小板聚集,IC_(50)为254μmol/L,对MDA的生成也有抑制作用。ASA不能对抗凝血酶引起的血小板聚集,但能显著抑制MDA的生成。提示,Oxy抑制血小板聚集的作用可能与影响PAF生成有关,对MDA生成的抑制可能影响了AA的游离。     

异亚丙基莽草酸抗血栓作用的实验研究

目的研究异亚丙基莽草酸(ISA)对大鼠动静脉环路血栓、大脑中动脉栓塞及血小板聚集的对抗作用及机制。方法用动静脉环路血栓及三氯化铁致大脑中动脉栓塞(MCAT)模型观察药物作用;并研究了ISA体内、外给药对血小板聚集的影响。结果ISA 25,50,100及200 mg·kg^-1 ig均可显著降低大鼠体外血栓重量;ISA 50,100,200 mg·kg^-1 ig可明显改善MCAT模型大鼠神经症状;ISA 100及200 mg·kg^-1 ig MCAT模型大鼠脑梗塞范围分别下降27.8%和31.6%;另外,ISA体内、外给药对ADP和胶原诱导的血小板聚集有明显的抑制作用。结论ISA可能通过抗血小板聚集作用抑制血栓的形成。     

三乙酰莽草酸对凝血酶和局灶性脑缺血再灌注诱导的血小板与白细胞粘附的作用及其机制

目的：研究三乙酰莽草酸（TSA）对凝血酶和局灶笥脑缺血再灌注诱导的血小板与中性粒细胞粘附及活化血小板膜P-选择素表达的作用。方法：观察玫瑰花环形成率作为血小板与中性粒细胞粘附率指标,并用流式细胞仪测定血小板表达P-选择素的表达。结果：TSA10-1000μmol/L可明显抑制凝血酶0.4kU/L诱导的血小板与中性粒细胞的粘附。TSA50-200mg/kg剂量依赖性抑制大脑中动脉阻断3h再灌注21h引起的血小板与中性粒细胞的粘附。TSA可明显抑制凝血酶诱导的血小板P-选择素的表达和ADP5μmol/L诱导的全血中血小板膜表面P-选择素的表达。结论：脑缺血再灌注和凝血酶引起血小板和中性粒细胞粘附,TSA对P-选择素表达的影响可能是其抑制血小板与中性粒细胞粘附的重要机制。     

Novel inhibitory actions on platelet thromboxane and inositolphosphate formation by xanthones and their glycosides

Xanthones and their glycosides were tested for their antiplatelet activities in washed rabbit platelets. Tripteroside acetate and norathyriol acetate were the most potent inhibitors. Tripteroside acetate inhibited platelet aggregation and ATP release induced by ADP, arachidonic acid, platelet-activating factor (PAF), collagen, ionophore A23187 and thrombin. The IC50 values of tripteroside acetate toward arachidonic acid- (100 microM) and collagen- (10 micrograms/ml) induced platelet aggregation were 10 and 30 micrograms/ml respectively. It inhibited thromboxane B2 formation of washed platelets caused by arachidonic acid, collagen, thrombin and ionophore A23187 and also that caused by the incubation of lysed platelet homogenate with arachidonic acid. Tripteroside acetate decreased the formation of inositolphosphate caused by thrombin, collagen and PAF, whereas it had no direct effect on fibrinogen-platelet interaction. It is concluded that xanthone derivatives inhibited platelet aggregation and release reaction by diminishing thromboxane formation and phosphoinositide breakdown.     

海兰地嗪对血小板聚集的影响及机理探讨

海兰地嗪(Her)体外对胶原,ADP,A23187和AA诱导的大鼠血小板聚集有明显抑制作用,其IC_(50)分别为14.5,41.6,44.1和48.3μg/ml。Her对AA诱导的大鼠血小板MDA生成不能抑制,但能升高兔血小板cAMP水平和抑制凝血酶诱导的人血小板胞浆内游离钙离子浓度升高。Her的抗血小板聚集作用机理可能与升高血小板内cAMP水平和抑制细胞内游离钙离子浓度升高有关。     

Effects of salicylic and acetylsalicylic acid alone and in combination on platelet aggregation and prostanoid synthesis in man.

The present study was designed to investigate the effects of salicylate on the antiplatelet action of acetylsalicylic acid as well as on in vivo prostanoid formation and platelet function in healthy volunteers. In the first study six female volunteers received 350 mg acetylsalicylic acid intravenously, with and without previous oral administration of sodium salicylate (1200 mg daily for 3 days). Urinary prostanoid excretion as well as platelet aggregation and thromboxane formation were measured before and during salicylate and after acetylsalicylic acid. In the second study seven female volunteers received sodium salicylate (52.6 mg kg-1) or acetylsalicylic acid (60.7 mg kg-1) for 8 days in a randomized cross-over protocol. Urinary prostanoid excretion, platelet aggregation and thromboxane formation as well as salicylate plasma concentrations were determined before, during and after administration of each drug. Sodium salicylate did not impair the complete suppression of arachidonic acid-induced platelet thromboxane formation and aggregation obtained by the single intravenous dose of acetylsalicylic acid in the first study. Sodium salicylate in the second study did not affect urinary excretion of prostaglandin E2, its major urinary metabolite (7 alpha-hydroxy-5,11-diketo-tetranor-prostane-1,16-dioic acid), and 2,3-dinor-6-keto-prostaglandin F1 alpha, the main urinary metabolite of epoprostenol (prostacyclin, PGI2). In contrast, acetylsalicylic acid significantly decreased excretion rates of these prostanoids by 64, 59 and 61%, respectively. In both studies platelet aggregation and thromboxane formation induced by collagen, thrombin or arachidonic acid were not significantly affected by salicylate administration, whereas acetylsalicylic acid inhibited platelet aggregation induced by all three agents as well as thrombin- and arachidonic acid induced thromboxane formation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effect of cefaclor on guinea pig platelet aggregation in vitro

Effects of cefaclor (3-chloro-7-D-(2-phenyl-glycinamido)-3-cephem-4-carboxylic acid) on PAF, ADP, collagen, endotoxin, and thrombin-induced platelet aggregation were examined in vitro with the use of guinea pig platelet-rich plasma and washed platelets. PAF, even at concentrations lower than its minimum effective concentration, enhanced ADP- or endotoxin-induced platelet aggregation and prolonged the time to attain the maximum aggregation. PAF also enhanced collagen-induced platelet aggregation and shortened the lag time. Cefaclor (CCL) inhibited the PAF, ADP or thrombin induced platelet aggregation and shortened their maximum aggregation times at higher concentrations such as 300 micrograms/ml or more. CCL also inhibited the collagen-induced platelet aggregation and prolonged the lag time, but showed no effect on endotoxin-induced platelet aggregation. The effect of CCL was almost the same as that of latamoxef (LMOX). CCL and LMOX, however, showed no effect on cellular Ca2+ increase produced by PAF, ADP, or thrombin, suggesting that the inhibitory effect of CCL and LMOX on platelet aggregation is caused by the inhibition of fibrinogen binding to the glycoprotein IIb/IIIa complex.     

The novel and orally active thrombin receptor antagonist E5555 (Atopaxar) inhibits arterial thrombosis without affecting bleeding time in guinea pigs

Thrombin is a powerful agonist for platelets, the action of which is mediated by the thrombin receptor protease-activated receptor-1 (PAR-1). Recently, we discovered that E5555 (1-(3-tert-butyl-4-methoxy-5-morpholinophenyl)-2-(5,6-diethoxy-7-fluoro-1-imino-1,3-dihydro-2H-isoindol-2-yl) ethanone hydrobromide) is a potent thrombin receptor antagonist. We evaluated the anti-platelet and anti-thrombotic effects of E5555. E5555 inhibited the binding of a high-affinity thrombin receptor-activating peptide ([(3)H]haTRAP) to PAR-1 with a half maximal inhibitory concentration (IC(50)) value of 0.019μM. E5555 showed potent inhibitory effects on human platelet aggregation induced by thrombin and TRAP with IC(50) values of 0.064 and 0.031μM, respectively, but had no effect on platelet aggregation induced by either ADP or collagen. Similarly, E5555 showed potent and selective inhibitory effects on guinea pig platelet aggregation induced by thrombin and TRAP with IC(50) values of 0.13 and 0.097μM, respectively. The antithrombotic activity of E5555 in vivo was evaluated in a photochemically-induced thrombosis (PIT) model using guinea pigs. Oral administration of E5555 at 30 and 100mg/kg prolonged the time to occlusion by 1.8-fold and 2.4-fold, respectively, compared with controls. Furthermore, E5555 did not prolong bleeding time in guinea pigs at the highest tested dosage of 1000mg/kg. The drug interactions between E5555 and tissue plasminogen activator (tPA) were evaluated. Intravenous administration of 1mg/kg tPA significantly prolonged bleeding time, and its effects were not altered by the oral co-administration of 300mg/kg E5555. These results suggest that E5555 could be a therapeutic option for atherothrombotic disease.