| Thrombosis intimidates mankind's life and health seriously, and has already become dominating death reason. According to recent statistical data from department of health, in our nation, there are more than five million cardiocerebral vascular patients now, 1,500,000 new patients and 200,000 death cases in every year. Among them, 50%-70% patients suffered from paralysis or aphasis etc. Lots of animal and clinical test proved that thrombolytic thearpy is very effective to decrease disabled rate and mortality from thrombosis. Current fibrinolytic enzymes available for clinical use are mostly plasminogen activators. Despite their widespread use, all these agents have undesired side effects. Therefore the search for new fibrinolytic enzymes from various sources is being continued.On the base of small-sized fermentation, liquid and solid fermentation technologies of the fibrinolytic enzyme from Rhizuopus chinensis were optimized. Animal test about the acute toxicity and medical effect of the fibrinolytic enzyme were done.The research result that liquid fermentation technology of Rhizuopus chinensis was amplified indicated: productivity of the fibrinolytic enzyme went up to peak value according to the follow conditions in 5L auto-fermentor. The conditions were nature pH, inoculum size 20%, 200 rpm, fermentation process 60h, beginning pH 4.3, 26℃ after 28h. Productivity of the fibrinolytic enzyme went up to 25U/mL by above conditions.The research result on solid fermentation technology of Rhizuopus chinensis 12 # indicated: the appropriate conditions were beginning pH 5.0, beginning moisture content 0.75mL/g dry substance, fermentation humidity 70%, quantity of inoculation 1×10~7spore/g, beginning ventilation 0.8vvm, 0.7vvm after 30h, 28℃, fermentation time 60h. Productivity of the fibrinolytic enzyme went up to peak value by above conditions.Purification process of the fibrinolytic enzyme from Rhizuopus chinensis was researched and ascertained. The process was Octyl-Sepharose Fast Flow, Phenyl-Sepharose HP, SP-Sepharose HP. The purified enzyme was homogeneous, as examined by SDS-PAGE and PAGE.Recently it become more popular that thrombolytic cure is significantly effective to decrease thrombus disease fatality rate and disabling rate, therefore, thrombolytic drug's research become current research focus and is more attractive. In our study's acute toxicity's maximal tolerance dose is above 25g/kg.bw, this is to say, this drug is actually non-toxic substance.The results that carotid artery thrombus can be seen by eyes testified that rat thrombus model was successfully created. Fibrinolytic enzyme produced by Rhizuopus chinensis can obviously inhibit carotid artery thrombus formation and vessel occlusion. In electron microscope, thrombolysis experiments showed that the fibrinolytic enzyme had the ability of inhibiting thrombus formaion through themethod of artery and vein bypass and carotid artery thrombus formation method.Our study about thrombolysis of the fibrinolytic enzyme demonstrated that:(l)the fibrinolytic enzyme can decrease the content of fibrinogen and euglobin dissolving time, enhancing the content of D-dimer, which suggested that it can accelerate fibrous protein dissolving by activating rat plasminogen and increasing plasmin activity.(2) Rabbit platelet aggregation experiment results testified that the fibrinolytic enzyme can significantly decrease arachidonic acid induced platelet rate and ADP adenosine diphosphate and collagen induced platelet accumulation rate partly.(3)The experiments of SOD contents and MDA can testify that the fibrinolytic enzyme can increase free radical clearing enzyme, reducing free redical creation, balance free redical metabolism and protect brain cells.(4) In the study of blood movement, the fibrinolytic enzyme can decrease rat whole blood conglutinating ability, haematocrit(HCT), red blood cell aggregation index, blood plasma conglutinating, which suggested that all kinds of factors affected the thrombus formation and development.
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