amylase

The full name of amylase (AMY or AMS) is 1,4-α-D-glucan hydrolase, which catalyzes the hydrolysis of starch and glycogen to produce glucose, maltose and dextrin containing α1,6-glycosidic linkages. Amylase is mainly secreted by the pancreas and salivary glands, and tissues such as lung, liver, thyroid, and fat also contain this enzyme. The determination is mainly colorimetric and rate methods. Basic Information Specialist classification: Digestive examination classification: biochemical examination Applicable gender: whether men and women apply fasting: fasting Analysis results: Below normal: In various liver diseases, blood and urine amylase are often reduced at the same time. Normal value: Sulf-starch colorimetric serum amylase: 800-1800U/L Sulfur-starch colorimetric urine amylase: 1000-12000U/L Above normal: Serum amylase assay is mainly used for the diagnosis of acute pancreatitis. It usually begins to rise 6 to 12 hours after the onset, peaks at 12 to 24 hours, and returns to normal after 2 to 5 days. Therefore, the serum amylase activity is significantly elevated, which is of great value in the early diagnosis of acute pancreatitis. Urinary amylase began to increase at 12 to 24 hours after onset, and lasted for a long time, and the decrease was slower than serum amylase. Therefore, urine amylase was more valuable in the late stage of pancreatitis. Chronic pancreatitis, pancreatic cancer, acute appendicitis, ulcerative perforation, intestinal obstruction, mumps, salivary gland and other serum amylase can be elevated. In renal dysfunction, blood amylase is elevated and urinary amylase is decreased. negative: Positive: Tips: Serum amylase determination is mainly used for the diagnosis of acute pancreatitis. Normal value 1, sulfo-starch colorimetry Serum 800 ~ 1800U / L; Urine 1000 ~ 12000U / L. 2, p-nitrobenzene malt heptasaccharide method serum (slurry) 100 ~ 220U / L, urine 120 ~ 1200U / L. Clinical significance Serum amylase assay is mainly used for the diagnosis of acute pancreatitis. It usually begins to rise 6 to 12 hours after the onset, peaks at 12 to 24 hours, and returns to normal after 2 to 5 days. Therefore, the serum amylase activity is significantly elevated, which is of great value in the early diagnosis of acute pancreatitis. Urinary amylase began to increase at 12 to 24 hours after onset, and lasted for a long time, and the decrease was slower than serum amylase. Therefore, urine amylase was more valuable in the late stage of pancreatitis. Chronic pancreatitis, pancreatic cancer, acute appendicitis, ulcerative perforation, intestinal obstruction, mumps, salivary gland and other serum amylase can be elevated. In renal dysfunction, blood amylase is elevated and urinary amylase is decreased. In various liver diseases, blood and urine amylase are often reduced at the same time. Low results may be diseases: high liver disease results may be diseases: acute pancreatitis, pancreatic cancer considerations 1. Sulfur-starch colorimetric method: (1) Serum and heparin anticoagulated plasma results were consistent, while EDTA-Na2, oxalate, citrate, and sodium fluoride inhibited AMS activity, resulting in low results. (2) The enzyme activity is significantly increased, that is, when the absorbance of the measuring tube is less than half of the absorbance of the blank tube, the substrate should be increased by the dilution factor, or the sample addition amount can be reduced due to the relative shortage of the substrate, and the measurement result is multiplied by the dilution factor. (3) AMS activity in saliva is high and should be prevented from entering. (4) If the starch base liquid appears turbid or floc, suggesting deterioration or contamination, it should be reconstituted. (5) The concentration of iodine solution can affect the measurement results. Generally, the iodine application solution should be reconstituted for more than one month. 2, p-nitrobenzene malt heptasaccharide method: (1) When ΔA/min>0.15, the specimen should be diluted 10 times with physiological saline and the measurement result multiplied by the dilution factor. (2) The kits, components and methods are not the same and should be subject to the instructions. Inspection process Sulf-starch colorimetric method. Not suitable for the crowd no. Adverse reactions and risks no.