ENDOTHELIUM-DEPENDENT VASORELAXATIONS IN RESPONSE TO AGGREGATING PLATELETS ARE IMPAIRED IN REVERSED VEIN GRAFTS
ENDOTHELIUM-DEPENDENT VASORELAXATIONS IN RESPONSE TO AGGREGATING PLATELETS ARE IMPAIRED IN REVERSED VEIN GRAFTS
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DOI：
10.1067/mva.1990.20925
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发表时间：
1990-08-01
影响因子：
4.3
通讯作者：
VANHOUTTE, PM
中科院分区：
文献类型：
--
作者：
KOMORI, K;GLOVICZKI, P;VANHOUTTE, PM
血管内皮细胞释放的因子(S)是有效的血管扩张剂和血小板聚集的抑制物。进行实验以确定静脉移植物对聚集的血小板的内皮依赖性反应是否发生改变。将16只兔颈静脉段逆行移植到颈动脉内。4周后取材(14/16)，观察血管内皮依赖性反应。对照静脉中聚集的血小板、二磷酸腺苷和5-羟色胺可引起内皮依赖性的松弛。APYrase(腺二磷酸酶和三磷酸腺苷酶)可减弱血小板引起的松弛，但5-羟色胺能受体阻滞剂甲硫氨酸不能减弱这种松弛。在静脉移植物中，对聚集的血小板的反应缺乏内皮依赖性的松弛，只有可以被甲硫平减弱的收缩被观察到。在移植静脉中，对二磷酸腺苷的内皮依赖性松弛反应减少，而对5-羟色胺的反应仅观察到非内皮依赖性的收缩。甲硫西平可减弱这些收缩。这些结果提示：(1)兔颈静脉内皮细胞对聚集的血小板反应主要由腺苷二磷酸介导的抑制作用；(2)静脉移植物对聚集的血小板反应的内皮依赖性松弛功能受损，这是由于二磷酸腺苷引起的内皮依赖性松弛反应减弱，5-羟色胺引起的内皮非依赖性收缩反应增强。静脉移植物内皮依赖性反应的这种损害可能是移植物失败的原因之一。
The endothelium releases factor(s) that are potent vasodilators and inhibitors of platelet aggregation. Experiments were performed to determine whether the endothelium-dependent responses to aggregating platelets are altered in vein grafts. Segments of jugular veins were grafted in the reverse position into the carotid arteries in 16 rabbits. After 4 weeks the patent grafts (14 of 16) were removed, and the endothelium-dependent responses were examined in vitro. In control veins aggregating platelets, adenosine diphosphate, and serotonin caused endothelium-dependent relaxations. The platelet-induced relaxations were attenuated by apyrase (adenosine diphosphatase and adenosine triphosphatase) but not by methiothepin (serotonergic blocker). In vein grafts, endothelium-dependent relaxations in response to aggregating platelets were absent, and only contractions that could be attenuated by methiothepin were observed. In vein grafts, endothelium-dependent relaxations in response to adenosine diphosphate were reduced, and only endothelium-independent contractions were observed in response to serotonin. These contractions were attenuated by methiothepin. These results suggest that (1) the endothelium exerts an inhibitory effect mediated mainly by adenosine diphosphate in response to aggregating platelets in rabbit jugular veins and (2) endothelium-dependent relaxations in response to aggregating platelets are impaired in vein grafts because of reduced endothelium-dependent relaxations in response to adenosine diphosphate and augmented endothelium-independent contractions in response to serotonin. This impairment of endothelium-dependent responses in vein grafts may contribute to failure of the grafts.