Lactate dehydrogenase (LDH, LD)

Lactate dehydrogenase is a glycolytic enzyme. Lactate dehydrogenase is present in the cytoplasm of all tissue cells in the body, with a high kidney content. Lactate dehydrogenase is an enzyme that catalyzes the production of lactic acid by pyruvate and is present in almost all tissues. There are five forms of isozymes, namely LDH-1 (H4), LDH-2 (H3M), LDH-3 (H2M2), LDH-4 (HM3) and LDH-5 (M4), which can be separated by electrophoresis. . The distribution of LDH isozymes has obvious tissue specificity, so it can be used to diagnose diseases according to their tissue specificity. LDH2 in serum of normal people, >LDH1. If myocardial enzymes are released into the blood, LDH1>LDH2 can be used to diagnose myocardial disease. Basic Information Specialist classification: cardiovascular examination classification: biochemical examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: Reduced by X-ray exposure. Normal value: Serum: 100-300U/L Urine: 560-2050U/L Above normal: Increased in hepatitis, cirrhosis, liver cancer, myocardial infarction, striated muscle injury, myocarditis, malignant tumor, kidney disease, pulmonary infarction, megaloblastic anemia, leukemia, malignant lymphoma and pregnancy. negative: Positive: Tips: Do not eat too greasy, high-protein foods the day before the blood draw, avoid heavy drinking. The alcohol content in the blood directly affects the test results. After 8 pm on the day before the medical examination, you should fast, so as not to affect the test. Normal value Serum: 100 ~ 300U / L; Urine: 560 ~ 2050U / L; The cerebrospinal fluid content is 1/10 of the serum. Clinical significance Increased in hepatitis, cirrhosis, liver cancer, myocardial infarction, striated muscle injury, myocarditis, malignant tumor, kidney disease, pulmonary infarction, megaloblastic anemia, leukemia, malignant lymphoma and pregnancy. Reduced by X-ray exposure. High results may be diseases: myocarditis, tachycardia, ischemic polymorphic ventricular tachycardia, atrial reentry tachycardia, bundle branch reentry ventricular tachycardia, primary cardiac lymph Tumor, non-paroxysmal sinus tachycardia, cirrhosis ascites, paroxysmal ventricular tachycardia, pediatric atrial tachycardia First, the precautions before blood draw 1, do not eat too greasy, high-protein food the day before the blood, to avoid heavy drinking. The alcohol content in the blood directly affects the test results. 2. After 8 pm on the day before the medical examination, fasting should be done to avoid affecting the test. 3, should relax when taking blood, to avoid the contraction of blood vessels caused by fear, increase the difficulty of blood collection. Second, should pay attention after blood draw 1. After blood is drawn, local compression is required at the pinhole for 3-5 minutes to stop bleeding. Note: Do not rub, so as not to cause subcutaneous hematoma. 2, the pressing time should be sufficient. There is a difference in clotting time for each person, and some people need a little longer to clotting. Therefore, when the surface of the skin appears to be bleeding, the compression is stopped immediately, and the blood may be infiltrated into the skin due to incomplete hemostasis. Therefore, the compression time is longer to completely stop bleeding. If there is a tendency to bleed, the compression time should be extended. 3, after the blood draw symptoms of fainting such as: dizziness, vertigo, fatigue, etc. should immediately lie down, drink a small amount of syrup, and then undergo a physical examination after the symptoms are relieved. 4. If there is localized congestion, use a warm towel after 24 hours to promote absorption. Inspection process Immediately after venous blood collection, the test is performed. Detection method: (1) Colorimetric method: Mix the reagent, place it at room temperature for 5 min, at a wavelength of 440 nm, the cuvette has a light path of 1.0 cm, adjust the zero point of distilled water, read the absorbance of each tube, and check the standard curve with the difference of AU-AC. Out LDH vitality unit. (2) Continuous monitoring method: Each laboratory can operate according to the model and manual of the biochemical automatic instrument. The main parameters are 340nm wavelength, 37 ° C, aspirate sample 500μl, continuous monitoring time 60s, the ratio of sample to reagent volume is 1:50. Not suitable for the crowd Generally no taboos. Adverse reactions and risks 1. Infection: Pay attention to aseptic operation when collecting blood, avoid contamination of water and other parts at the blood collection site to avoid local infection. 2, bleeding: after the blood is given a full compression time, especially coagulopathy, bleeding tendency, to avoid local subcutaneous oozing, bruising and swelling.