银杏叶提取物与阿司匹林抗血栓栓塞作用的比较研究

Comparison of Effects of Ginkgo Biloba Extract and Aspirin on Thromboembolism

目的探讨银杏叶提取物(Ginkgo biloba extracts,GBE)对血栓栓塞的作用及机制,与小剂量阿司匹林对比研究。方法通过在体电刺激颈动脉制备大鼠血栓栓塞模型,动态观察颈动脉栓塞形成程度同时观察血管栓塞显微照片,研究评价在相当人临床用量的GBE和小剂量阿司匹林对血栓栓塞的抑制作用;采用放免法测定血栓形成大鼠血浆前列环素和血栓素的含量,研究探讨GBE抑制血栓形成的机制。采取冷应激法制备大鼠血液流变学病理模型,测定全血粘度、血浆粘度、血沉和细胞压积指标,研究和评价GBE和小剂量阿司匹林对血液流变学的影响。结果 6.7 mg/kg GBE、20 mg/kg GBE和9 mg/kg阿司匹林均使大鼠颈动脉栓塞程度明显减轻,明显对抗电刺激引发的血栓素升高和前列环素水平下降;20 mg/kg GBE和9 mg/kg阿司匹林均明显减轻应激状态全血粘度、血浆粘度和细胞压积指标的增高,6.7 mg/kg GBE仅能抑制细胞压积的增高。通过对比分析,9 mg/kg阿司匹林抑制血栓栓塞和血液流变学异常增高作用,强于6.7 mg/kg GBE组,与20 mg/kg GBE组基本相当。结论相当人临床用量的GBE对大鼠血栓栓塞有抑制作用,明显弱于小剂量阿司匹林,可对抗血浆前列环素和血栓素的异常变化,对多种血液流变学指标异常增高的影响不明显;剂量提高3倍的GBE,对抗大鼠血栓栓塞和血液流变学异常增高作用,与小剂量阿司匹林基本相当。

Objective To study effects and mechanisms of the Ginkgo biloba extract（GBE）on thromboembolism compared with the effects of low-dose aspirin.Methods The degree of carotid artery thrombus caused by electricity stimulus in rats was observed dynamically,meanwhile vascular thrombosis micrographs were observed and the inhibitory effect of small-doses aspirin on thromboembolism was studied;contents of PGI2 and TXA2 in the blood plasma of rat were determined by radioimmunoassay methods and mechanisms of GBE on thromboembolism were studied.Cold stress method was applied for rats blood rheology pathological model and whole blood viscosity,plasma viscosity,blood sedimentation and cell deposited index were determined,and meanwhile the effect of low-dose GBE,high-dose GBE and low-dose aspirin on hemorheology were analyzed and evaluated.Through the contrast analysis,the 9 mg/kg aspirin inhibited thromboembolism and exceptional increasing role of blood rheology in rats were more potent than 6.7 mg/kg GBE,and nearly as potent as 20 mg/kg GBE.Results 6.7 mg/kg GBE,20 mg/kg GBE and 9 mg/kg aspirin significantly reduced the degree of the carotid artery embolism in rats and obviously protected the rising of TXA2 and the dropping of PGI2 in blood plasma of the rats whose carotid artery was stimulated by electrical current;20 mg/kg GBE and 9 mg/kg aspirin significantly reduced whole blood viscosity,plasma viscosity and cell deposited index increased by stress,6.7 mg/kg GBE only inhibited the increase of hematocrit.Comparing the potency of GBE with aspirin,the effect of 9 mg/kg aspirin is better than 9 mg/kg EGBL,weaker than 18 mg/kg PC.Conclusion The GBE,at the corresponding clinical dosage,might inhibit thromboembolism in rat,which was obviously weaker than small-doses aspirin,and might reduce the abnormal changes of PGI2 and TXA2 in the blood plasma of rat,and might have no obvious effect on a variety of exceptional increasing hemorheology indices;The GBE,at 3-time dosage,showed nearly the same efficacy as small-doses aspirin on thromboembolism and abnormal changes of a variety of exceptional increasing hemorheology indices in rats.