Hematin: unique effects of hemostasis.
Hematin: unique effects of hemostasis.
复制标题
血红素：具有独特的止血作用。
作者：
R. Glueck;D. Green;I. Cohen;C. Ts'ao
血红素在临床上可用于治疗急性间歇性卟啉病。最近，有报道称血红素诱导的凝血功能障碍，我们治疗的一名患者在血红素治疗期间流血的。在3个不同的情况下，输注血红素（4 mg/kg）诱导血小板减少症、凝血酶原时间和部分凝血活酶时间延长。立止血时间，纤维蛋白原明显减少，纤维蛋白（原）降解产物（FDP）增加。然而，通过热沉淀法测定的纤维蛋白原无变化，鱼精蛋白副凝固试验为阴性，无红细胞碎裂，纤溶酶原和抗凝血酶III保持正常，排除弥散性血管内凝血的存在。此外，术前给予肝素，5000 U静脉注射，未能阻止立止血时间延长，并加重血小板减少症。在体外研究表明，血红素，0.1毫克/毫升，聚集血小板和诱导释放的14 C-血清素和三磷酸腺苷（ATP）。血红素也聚集洗涤或凝胶过滤的血小板，但对福尔马林固定的血小板没有影响。阿司匹林（0.12毫克/毫升），腺苷三磷酸，腺苷双磷酸酶，抑制聚集，表明血红素聚集血小板诱导腺苷二磷酸（ADP）的释放。血红素（0.07 mg/ml）使凝血酶逐渐失活，0.1 mg/ml使立止血时间延长。因此，血红素是独特的，因为它既诱导血小板聚集又抑制凝血。
Hematin is clinically useful in the treatment of acute intermittent porphyria. Recently, hematin-induced coagulopathy has been reported, and a patient we treated bled during hematin therapy. On 3 separate occasions, infusions of hematin (4 mg/kg) induced thrombocytopenia, prolongation of the prothrombin time, partial thromboplastin time. Reptilase time, and apparent decreases in fibrinogen and increases in fibrin(ogen) degradation products (FDP). However, fibrinogen assayed by heat precipitation was unchanged, the protamine paracoagulation test was negative, there was no red blood cell fragmentation, and plasminogen and antithrombin III remained normal, excluding the presence of disseminated intravascular coagulation. Furthermore, premedication with heparin, 5000 U i.v., failed to prevent the lengthening of the Reptilase time and exacerbated the thrombocytopenia. In vitro studies revealed that hematin, 0.1 mg/ml, aggregated platelets and induced the release of 14C-serotonin and adenosine triphosphate (ATP). Hematin also aggregated washed or gel-filtered platelets but had no effect on formalin-fixed platelets. Aggregation was inhibited by aspirin (0.12 mg/ml), adenosine triphosphate, and apyrase, suggesting that hematin aggregated platelets by inducing adenosine diphosphate (ADP) release. Hematin (0.07 mg/ml) progressively inactivated thrombin and 0.1 mg/ml prolonged the Reptilase time. Thus, hematin is unique in that it both induces platelet aggregation and inhibits coagulation.