A Comparison of Fibrinolysis of Clots from Venipuncture

静脉穿刺血栓纤溶作用的比较

• 批准号: 7215849
• 负责人: mcdonald k horne
• 金额: --
• 依托单位: CLINICAL CENTER
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/7215849
• 关键词: blood coagulation; blood disorder diagnosis; enzyme activity; enzyme inhibitors; extracellular matrix proteins; fibrinolysis; fingers; hemostatics; human subject; metalloendopeptidases; phlebotomy; protein degradation; proteolysis; tissue /cell culture; wound healing

The lysis of hemostatic blood clots is orchestrated by a complex array of biochemical pathways and regulated to allow the clot to disappear as a wound heals. If a clot dissolves too quickly, the wound may rebleed. The study of fibrinolysis has traditionally focused on blood obtained by atraumatic venipuncture, although such samples lack any components that might be contributed by the extravascular tissue, which is where hemostatic clots naturally exist. Therefore, we have compared the in vitro lysis rate of blood obtained by venipuncture and blood obtained by fingerstick, which passes through extravascular tissue in the process of bleeding. Clots are incubated for 2-48 hours, and their degradation is monitored by measuring proteolytic breakdown products in the serum. We have found that fingerstick clots lyse significantly faster than clots of venipuncture blood. We have assayed fingerstick and venipuncture samples for all the proteins known to be involved in fibrinolysis but have not found significant differences between the two. With the hypothesis that matrix metalloproteinases (MMPs) might be contributing to the lysis of fingerstick clots, we have added inhibitors of these enzymes to the blood samples when they are first obtained. The inhibitors change the lytic rate of fingerstick clots in different ways but have no obvious effect on the lysis of venipuncture clots. We will pursue this line of evidence by assaying samples for specific MMPs. If we can identify specific enzymes or inhibitors that are operative in fingerstick blood, we will look for abnormalities in these proteins in patients with undiagnosed bleeding disorders.

止血血凝块的溶解是由一系列复杂的生化途径精心安排的，并受到调节，使血凝块随着伤口愈合而消失。如果血块溶解得太快，伤口可能会再次出血。纤维蛋白溶解的研究传统上集中在通过非创伤性静脉穿刺获得的血液上，尽管这些样本缺乏任何可能由血管外组织贡献的成分，而血管外组织是止血凝块自然存在的地方。因此，我们比较了静脉穿刺采血和手指穿刺采血的体外裂解率，在出血过程中，静脉穿刺采血通过血管外组织。血块孵育2-48小时，通过测定血清中的蛋白水解分解产物来监测其降解情况。我们发现，手指穿刺血凝块的溶解速度明显快于静脉穿刺血凝块。我们已经检测了手指穿刺和静脉穿刺样本中所有已知参与纤溶的蛋白质，但没有发现两者之间的显著差异。假设基质金属蛋白酶（MMPs）可能有助于手指粘块的溶解，我们在首次获得血液样本时添加了这些酶的抑制剂。抑制剂通过不同方式改变手指血栓的溶解速率，但对静脉穿刺血栓的溶解无明显影响。我们将通过分析特定MMPs的样本来追踪这条证据线。如果我们能识别出在指血中起作用的特定酶或抑制剂，我们将在未确诊出血性疾病的患者中寻找这些蛋白质的异常。