tissue plasminogen activator (t-PA)

Tissue plasminogen activator is a single-chain glycoprotein, which is mainly synthesized and secreted by vascular endothelial cells and continuously released into the blood. It is widely present in various tissues of the body, and the liver is inactivated by tissue plasminogen activator. The main place. It has a high affinity for fibrin and then forms plasminogen with tyrosine plasminogen. Degradation of fibrin (original) and partial coagulation factors. It is a key substance in the fibrinolytic system. Basic Information Specialist classification: examination classification: blood examination Applicable gender: whether men and women apply fasting: fasting Tips: Eliminate tension and try to cooperate with the doctor. Normal value (1) Activity assay (t-PA: A, one of the chromogenic substrate methods) 0.3 IU/ml. (2) Activity assay (2 of t-PA: A chromogenic substrate method) 1.9 ± 0.7 IU/ml. (3) Antigen assay (t-PA: Ag) ELISA method 1 to 12 ng/ml. Clinical significance (1) Activity assay (t-PA: A, one of the chromogenic substrate methods) 1 Liver necrosis is often accompanied by abnormal fibrinolytic activity, and t-PA:A tends to increase due to the elimination of dysfunction. However, at the same time, the activity of t-PA is actually reduced due to the enhanced activity of PAI. Diseases with a tendency to thrombosis tend to have a decrease in t-PA activity. PA activity was reduced in patients with coronary heart disease and myocardial infarction. 2 Congenital t-PA activity enhancement has been reported. Patients with acute promyelocytic leukemia tend to have elevated t-PA. 3 Hereditary PA activity deficiency is autosomal dominant inheritance. The patient presented with multiple venous thrombosis. (2) Activity measurement (t-PA: A chromogenic substrate method 2) Increased 1t-PA:A indicates hyperactivity of fibrinolytic activity, found in primary and secondary fibrinolysis, such as DIC. A decrease in 2t-PA:A indicates a decrease in fibrinolytic activity and is seen in hypercoagulable states and thrombotic diseases. (3) Antigen assay (t-PA: Ag) ELISA The 1t-PA content increased with age, strenuous exercise and stress response, and venous retention led to an increase in t-PA content. 2 congenital t-PA content increase. 3 high blood fat, obesity, oral contraceptives, coronary heart disease, myocardial infarction, arterial thrombosis, ischemic stroke and other t-PA content decreased. Precautions (1) Activity assay (t-PA: A, one of the chromogenic substrate methods): 1 The concentration of heparin in plasma exceeds 1.5 IU/ml, which has an effect on this test. 2 It is best not to use a tourniquet when collecting blood. After pressurization, it will cause t-PA to enter the blood. 3 samples must be acidified. Otherwise it is greatly affected by PAI. (2) Antigen assay (t-PA: Ag) ELISA: ELISA is a specific and sensitive immunological assay. Therefore, the conditions of each test must be strictly controlled. Inspection process t-PA: A chromogenic substrate method. Not suitable for the crowd Generally no taboos. Adverse reactions and risks No.