Amylase
Updates to Article Attributes
Serum amylaseAmylase is widely employed as a marker of acute pancreatitis and a significant elevation is diagnostic.
Physiology
α-amylase is a digestive enzyme that is predominantly secreted by the acinar cells of the exocrine pancreas. It is also secreted by the salivary glands. Pancreatic amylase is encoded by AMY2, a geneand salivary amylase by AMY1, both genes on chromosome 1 5.
The main function of the amylases is to initiate the digestion of complex polysaccharides, primarily starch, to itstheir constituent simple sugars. This starts in the mouth with salivary α-amylase, which continues to work in the stomach (it is chemically protected from the gastric acid). In the small bowel, starting in the duodenum, pancreatic α-amylase digests the dietary carbohydrate, aided by remnant salivary α-amylase 3.
Starch is mainly composed of two glucose polymers: amylopectin (75%) and amylose (25%), and the main action of amylase is to break their internal α1,4 linkages. This results in the formation of oligosaccharides, which are primarily maltose, maltotriose, and α-limit dextrins 3.
Interpretation
The salivary glands and the pancreas account for most of the normal serum amylase found in a well individual 1. These two amylase isoforms can be distinguished by laboratory assay. Normal serum amylase reference range is 19 units/litre (U/L) - 86 U/L.
Causes of hyperamylasaemia
Amylase is found in small bowel intraluminal fluid and therefore bowel stasis can lead to abnormal absorption of the enzyme.
- pancreatitis
- other pancreatic assaults
- ERCP/EUS: instrumentation of the main pancreatic duct
- pancreatic trauma
- bowel disease
- bowel ischaemia/infarction
- bowel perforation
- salivary gland pathology
- reduced homeostatic removal of amylase
- renal failure
- macroamylasaemia
- chronic alcoholism
- postsurgical
- especially coronary arterial bypass grafting (CABG)
- lactic acidosis
- eating disorders
- anorexia nervosa
- bulimia
- ectopic amylase secretion by cancer
- Gullo syndrome
Causes of hypoamylasaemia
The main cause of a low serum amylase is chronic pancreatitis 4.
Rare individuals/families with isolated pancreatic amylase deficiency have been seen. They exhibit signs and symptoms of carbohydrate malabsorption.
-<p><strong>Serum amylase</strong> is widely employed as a marker of <a href="/articles/acute-pancreatitis">acute pancreatitis</a> and significant elevation is diagnostic. </p><h4>Physiology</h4><p>α-amylase is a digestive enzyme that is predominantly secreted by the acinar cells of the exocrine pancreas. It is also secreted by the salivary glands. Pancreatic amylase is encoded by <em>AMY2</em>, a gene on chromosome 1 <sup>5</sup>.</p><p>The main function of the amylases is to initiate the digestion of complex polysaccharides, primarily starch, to its constituent simple sugars. This starts in the mouth with salivary α-amylase, which continues to work in the stomach (it is chemically protected from the gastric acid). In the small bowel, starting in the duodenum, pancreatic α-amylase digests the dietary carbohydrate, aided by remnant salivary α-amylase <sup>3</sup>.</p><p>Starch is mainly composed of two glucose polymers: amylopectin (75%) and amylose (25%), and the main action of amylase is to break their internal α1,4 linkages. This results in the formation of oligosaccharides, which are primarily maltose, maltotriose, and α-limit dextrins <sup>3</sup>.</p><h4>Interpretation</h4><p>The salivary glands and the pancreas account for most of the normal serum amylase found in a well individual <sup>1</sup>. These two amylase isoforms can be distinguished by laboratory assay. Normal serum amylase reference range is 19 units/litre (U/L) - 86 U/L.</p><h4>Causes of hyperamylasaemia</h4><p>Amylase is found in small bowel intraluminal fluid and therefore bowel stasis can lead to abnormal absorption of the enzyme. </p><ul>- +<p><strong>Amylase</strong> is widely employed as a marker of <a href="/articles/acute-pancreatitis">acute pancreatitis</a> and a significant elevation is diagnostic. </p><h4>Physiology</h4><p>α-amylase is a digestive enzyme that is predominantly secreted by the acinar cells of the exocrine pancreas. It is also secreted by the salivary glands. Pancreatic amylase is encoded by <em>AMY2</em>, and salivary amylase by <em>AMY1</em>, both genes on chromosome 1 <sup>5</sup>.</p><p>The main function of the amylases is to initiate the digestion of complex polysaccharides, primarily starch, to their constituent simple sugars. This starts in the mouth with salivary α-amylase, which continues to work in the stomach (it is chemically protected from the gastric acid). In the small bowel, starting in the duodenum, pancreatic α-amylase digests the dietary carbohydrate, aided by remnant salivary α-amylase <sup>3</sup>.</p><p>Starch is mainly composed of two glucose polymers: amylopectin (75%) and amylose (25%), and the main action of amylase is to break their internal α1,4 linkages. This results in the formation of oligosaccharides, which are primarily maltose, maltotriose, and α-limit dextrins <sup>3</sup>.</p><h4>Interpretation</h4><p>The salivary glands and the pancreas account for most of the normal serum amylase found in a well individual <sup>1</sup>. These two amylase isoforms can be distinguished by laboratory assay. Normal serum amylase reference range is 19 units/litre (U/L) - 86 U/L.</p><h4>Causes of hyperamylasaemia</h4><p>Amylase is found in small bowel intraluminal fluid and therefore bowel stasis can lead to abnormal absorption of the enzyme. </p><ul>
-<li><a title="Gullo syndrome" href="/articles/gullo-syndrome">Gullo syndrome</a></li>- +<li><a href="/articles/gullo-syndrome">Gullo syndrome</a></li>
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