Amylase / characteristics

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Pancreatic amylase

Pankreatic amylase

α-amylase[1] [2][3][4][5][6][7][8][9][10](AMS, α-1,4-glucan-4-glucan hydrolase, EC 3.2.1.1) hydrolyses the α-1-4-glycoside bond; The pH optimum of α-amylase is between 7.0-7.2. It occurs in the body in two forms - as a salivary and pancreatic isoenzyme according to organ origin. Both isoforms of AMS differ from each other in the sugar component and can be distinguished electrophoretically or by precipitation using a special lectin or antibody[11]. α-amylase is formed in the acinar cells of the pancreas and accumulates in zymogenic granules. It enters the intestinal lumen in the form of pancreatic secretion (pancreatic juice) along with other digestive enzymes. Under physiological conditions, the enzyme molecule is not absorbed by the intestinal surface and the serum level is low, corresponding to the activity of the enzyme released into the circulation directly from the glandular cells, resp. lymphatic drainage. The molecular weight of α-amylase is 55,000. Α-Amylase is eliminated from the circulation in the kidneys by glomerular filtration. The macroform of the enzyme (macroamylase)[12][13][14][15][16] is formed by the binding of the enzyme to certain proteins in the blood serum, especially immunoglobulins, circulating immunocomplexes or other glycoproteins. The macroform of the enzyme has a significantly higher molecular weight (from 150,000 to 2,000,000) and is therefore not eliminated by glomerular filtration. For clinical diagnosis, serum and urinary α-amylase levels are determined and the amylase / creatinine clearance index is calculated.

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  1. ↑ CARROLL, Jennifer K, Brian HERRICK a Teresa GIPSON. Acute Pancreatitis: Diagnosis, Prognosis, and Treatment. American Family Physician [online]. 2007, vol. 75, no. 10, s. 1513-1520, dostupné také z <https://www.aafp.org/afp/2007/0515/p1513.pdf>. ISSN 0002-838X. 
  2. ↑ KOCNA, Petr a Tomáš ZIMA. Hyperamylazémie, laboratorní a klinické aspekty. Časopis lékařů českých [online]. 2006, vol. 145, s. 449-452, dostupné také z <https://www.prolekare.cz/casopis-lekaru-ceskych-clanek?id=3093>. ISSN 1803-6597.
  3. ↑ QUARINO, L, Q DANG a J HARTMANN. An ELISA method for the identification of salivary amylase. Journal of forensic sciences. 2005, vol. 50, no. 4, s. 873-876, ISSN 0022-1198. 
  4. ↑ SMITH, Ross C, James SOUTHWELL-KEELY a Douglas CHESHER. Should serum pancreatic lipase replace serum amylase as a biomarker of acute pancreatitis?. ANZ journal of surgery [online]. 2005, vol. 75, no. 6, s. 399-404, dostupné také z <https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1445-2197.2005.03391.x?cookieSet=1>. ISSN 1445-1433. 
  5. ↑ PANTEGHINI, Mauro, Ferruccio CERIOTTI a Franca PAGANI, et al. Recommendations for the routine use of pancreatic amylase measurement instead of total amylase for the diagnosis and monitoring of pancreatic pathology. Clinical Chemistry and Laboratory Medicine [online]. 2002, vol. 40, no. 2, s. 97-100, dostupné také z <https://www.degruyter.com/doi/abs/10.1515/CCLM.2002.017>. ISSN 1434-6621. 
  6. ↑ TREACY, John, Anthony WILLIAMS a Renz BAIS, et al. Evaluation of amylase and lipase in the diagnosis of acute pancreatitis. ANZ Journal of Surgery [online]. 2001, vol. 71, no. 10, s. 577-82, dostupné také z <https://onlinelibrary.wiley.com/doi/pdf/10.1046/j.1445-2197.2001.02220.x?cookieSet=1>. ISSN 1445-1433. 
  7. ↑ PEZZILLI, R, G TALAMINIL a L GULLO. Behaviour of serum pancreatic enzymes in chronic pancreatitis. Digestive and Liver Disease. 2000, vol. 32, no. 3, s. 233-237, ISSN 1590-8658. 
  8. ↑ KEIM, V, N TEICH a F FIEDLER, et al. A comparison of lipase and amylase in the diagnosis of acute pancreatitis in patients with abdominal pain. Pancreas. 1998, vol. 16, no. 1, s. 45-49, ISSN 0885-3177. 
  9. ↑ CHASE, CW, DE BARKER a WL RUSSELL. Serum amylase and lipase in the evaluation of acute abdominal pain. The American surgeon. 1996, vol. 62, no. 12, s. 1028-1033, ISSN 0003-1348. 
  10. ↑ MALFERTHEINER, P a J ENRIQUE DOMÍNGUEZ-MUÑOZ. Clinical and laboratory diagnosis of acute pancreatitis. Annali italiani di chirurgia. 1995, vol. 66, no. 2, s. 165-170, ISSN 0003-469X. 
  11. ↑ RACEK, Jaroslav, et al. Klinická biochemie. 2. vydání. Praha : Galén, 2006. 329 s. s. 87. ISBN 80-7262-324-9.
  12. ↑ BERMEJO, JF, J CARBONE a JJ RODRIGUEZ, et al. Macroamylasaemia, IgA hypergammaglobulinaemia and autoimmunity in a patient with Down syndrome and coeliac disease. Scandinavian journal of gastroenterology. 2003, vol. 38, no. 4, s. 445-447, ISSN 0036-5521. 
  13. ↑ LAWSON, GJ. Prevalence of macroamylasaemia using polyethylene glycol precipitation as a screening method. Annals of clinical biochemistry. 2001, vol. 38(Pt 1), s. 37-45, ISSN 0004-5632. 
  14. ↑ VENTRUCCI, M, A CIPOLLA a M MIDDONNO, et al. Macroamylase detection in serum using selective precipitation: a rapid and reliable assay. Italian journal of gastroenterology and hepatology. 1999, vol. 31, no. 9, s. 846-849, ISSN 1125-8055. 
  15. ↑ CUTOLO, M, A SULLI a A BARONE, et al. Macroamylasemia: a possible cause of unexplained hyperamylasemia in rheumatoid arthritis. British journal of rheumatology. 1995, vol. 34, no. 3, s. 290-292, ISSN 0263-7103. 
  16. ↑ HORTIN, GL, AL SUMMERFIELD a TR WILHITE, et al. Detection of autoantibodies to amylase by ELISA: comparison of detection of macroamylase and free autoantibody. Clinical chemistry[online]. 1994, vol. 40, no. 12, s. 2254-2259, dostupné také z <http://clinchem.aaccjnls.org/content/clinchem/40/12/2254.full.pdf,>. ISSN 0009-9147. 
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