Plasmin (PL) is produced by PLG under the action of its activator (PA) and is the most direct factor leading to fibrin degradation. Under physiological conditions, PL binds to PLG, t-PA, etc. on the surface of vascular endothelial cells. Once a small amount of fibrin is formed, PLG is activated to PL, and the latter partially degrades fibrin to avoid thrombosis and ensure blood flow. unobstructed.

Basic Information

Specialist classification: cardiovascular examination classification: biochemical examination

Applicable gender: whether men and women apply fasting: fasting

Tips: Do not take anticoagulant drugs, such as aspirin, before testing. Normal value

Plasmin activity

85.55% ± 27.83% (chromogenic substrate method).

21.1 ~ 48.9U (Congo red color method).

Clinical significance

1. The effect of exercise on the fibrinolytic system

In order to investigate the relationship between exercise level (medium and heavy) and coagulation and fibrinolysis system, Weiss et al. examined the expression of plasma thrombin, fibrin and plasmin in 12 healthy men before and after treading. The results showed that in moderate exercise, the t-PA antigen increased from 3.7±0.5 ng/ml to 14.6±1.8 ng/ml, P<0.01, and PAP increased from 2.1±0.3 nmol/L to 4.2±0.7 nmol/ L, P < 0.01. However, plasma prothrombin fragment 1+2 (pro-thrombinfragment1+2, F1+2), thrombin-antithrombin III complexes (TAT) and fibrin-opeptide A (FPA) ) but no significant changes. After severe exercise, the levels of t-PA and PAP were 2.5 and 2 times higher than the normal high limit, respectively, while the plasma F1+2, FAT and FPA were significantly increased in the normal range (P<0.01, <0.05, respectively). <0.01). Studies have shown that in healthy young individuals, exercise leads to increased clotting activity and also increases fibrinolytic activity. Moderate-intensity exercise only leads to the formation of plasmin, while fibrinolytic enzyme formation exceeds thrombin and fibrin during heavy-intensity exercise. Formation.

2, the significance of fibrinolysis hyperthyroidism

The activity of the fibrinolytic system in the body is due to the appearance of plasmin, and the activity of plasmin in the blood is regulated by the activator released into the blood. Therefore, the hyperfibrinolysis caused by various reasons, whether congenital or acquired, whether primary or secondary, the end result is excessive production of plasmin and lead to enhanced plasmin activity. The results of plasmin in patients with liver disease showed that plasma plasmin was significantly elevated in patients with acute hepatitis, chronic hepatitis and cirrhosis, indicating that plasmin activity was enhanced at this time.

3. Significance in prethrombotic state and thrombotic disease

Pre-thrombotic state and thrombotic disease often result in decreased plasmin activity (PL) due to decreased t-PA activity and content and increased PAI-1 activity. The level of α2-AP was decreased and the plasmin-α2-AP complex (PAP) was increased in patients with ischemic encephalopathy. The data showed that the level of PAP in patients with ischemic encephalopathy (1.09±0.45mg/L) was significantly higher than that in the normal control group. (0.59 ± 0.13 mg / L). Thrombotic diseases, such as acute myocardial infarction, pulmonary infarction, deep vein thrombosis, nephrotic syndrome, DIC and other secondary hyperfibrinolysis, increased PAP levels. Oikawa et al tested plasma PAP (PL-α2-AP) and D-Dimer in 42 children with nephrotic syndrome and found active PAP (0.67±0.48μg/ml) and D-Dimer (154) in nephrotic syndrome. The level of ±105 ng/ml) was significantly different from that of the stationary phase (PAP 0.43 ± 0.18 μg/ml, D-Dimer 72 ± 48 ng/ml) (P < 0.01, P < 0.001). Although thrombosis has not been found clinically, elevated levels of PAP and D-Dimer reflect the hypercoagulable state of the nephrotic syndrome.

4. Significance of thrombolytic therapy in thrombotic diseases

In thrombolytic diseases such as acute myocardial infarction, pulmonary embolism, venous thrombosis, etc., thrombolytic therapy (such as streptokinase, urokinase, t-PA or recombinant t-PA), due to exogenous fibrinolysis The action of the zymogen activator converts plasminogen to plasmin, thereby degrading fibrin (original) for the purpose of dissolving the thrombus. Therefore, the activity of plasmin after thrombolysis is increased. The plasmin-α2-AP complex (PAP or PIC) is increased, and it has been reported that the complex formed by α2-AP and plasmin (PAP) is a molecular marker that can sensitively react to activation of the fibrinolytic system. Plasma PAP was significantly increased when treated with thrombolytic drugs.

High results may be diseases: neonatal thrombocytopenic purpura, pediatric hemorrhagic disease, disseminated intravascular coagulation in children, thrombotic disease in the elderly, pregnancy with thrombotic disease, disseminated intravascular coagulation

It is forbidden to take anticoagulant drugs, such as aspirin, before testing.

Inspection process


1. Boric acid buffer (pH 7.8): 6.084 g of boric acid, 7.456 g of KOH, 500 ml of distilled water, 53 ml of 0.1 mmol/L NaOH solution, and distilled water to 1000 ml.

2, 1g / L Congo red solution: Congo red 0.5g plus 500ml of normal saline.

3. 1 mol/L HCl solution.

4. 50g/LCaCl2 solution.

5, the preparation of matrix powder: plasma and physiological saline, 50g / LCaCl2 solution in a ratio of 10:100:5, 37 ° C water bath for 60min, all the fibrin is rolled out with a glass rod, washed twice with physiological saline, squeezed , set in a 56 ° C incubator for drying. Take 10g of fibrin, add 100g of 1g/L Congo red solution, stir constantly in 37°C water bath, keep warm for 30min, centrifuge at 3000r/min for 10min, discard the supernatant, and wash repeatedly with pH7.8 boric acid buffer until the supernatant is colorless. The fibrin combined with Congo red was placed in a 56 ° C incubator for drying.

6, spectrophotometer.

Method of operation

Centrifuge the above solution, take the supernatant, spectrophotometer 600nm wavelength colorimetric, blank 0, measure the absorbance value, check the standard curve to get the plasmin activity.

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Adverse reactions and risks