一种体内溶栓活性优于总蚯蚓纤溶酶的组分

目的筛选高效低毒的蚯蚓纤溶酶单一组分。方法通过亲和色谱从赤子爱胜蚓获得含多组分的总蚯蚓纤溶酶(EFE)，经离子交换分离得到3个主要溶栓组分EfP-0-2，EfP-I-1和EfP-I-2，与EFE比较体内外溶栓效果和毒副作用。结果与其他组分比较，EfP-I-1的体外溶栓作用较强；当静脉注射4.5 mg·kg^-1时，各组分对纤维蛋白原的影响均不明显，只有EfP-I-1能显著溶解动静脉旁路血栓；当静脉注射达6 mg·kg^-1时，只有该组分对延长出血时间的影响不明显；急性毒性实验表明，该组分的LD₅₀是EFE的2.17倍。结论EfP-I-1有较高的体内外溶栓活性和较低的毒副作用。由于该组分在总EFE中所占比例较高，并易于分离纯化，故适于作为单一组分的溶栓药物进行开发。

A component of earthworm fibrinolytic enzyme having higher thrombolytic activity than total components in vivo

AIM: To select higher thrombolytic and lower toxic single component of earthworm fibrinolytic enzymes (EFE). METHODS: EFE containing total components were obtained by affinity chromatography from Eisenia fetida. Using ion-exchange chromatography to separate three main components EfP-0-2, EfP-I-1 and EfP-I-2 from EFE, their thrombolytic activity and toxicity were compared with EFE. RESULTS: Among these components, EfP-I-1 had higher thrombolytic activity in vitro. When 4.5 mg x kg(-1) of these components were injected, the contents of fibrinogen in rat serum were not affected, but only EfP-I-1 exhibited distinct thrombolytic activity. When 6.0 mg x kg(-1) of them were injected intravenously, the bleeding time was not evidently delayed only by EfP-I-1. The acute toxicity test showed that the LD50 of EfP-I-1 was higher than EFE by 2. 17 times. CONCLUSION: Because of distinct thrombolytic activity, lower toxicity in vivo, higher content in EFE and easy to purify, EfP-I-1 was adapted to be developed as a single component medicine for treating thrombus.