amylase

amylase

 [am´ĭ-lās]

an enzyme that catalyzes the hydrolysis of starch into simpler compounds. The α-amylases occur in animals and include pancreatic and salivary amylase; the β-amylases occur in higher plants. Measurement of serum α-amylase activity is an important diagnostic test for acute and chronic pancreatitis.

am·y·lase

(am'il-ās),

One of a group of amylolytic enzymes that cleave starch, glycogen, and related 1,4-α-glucans.

amylase

/am·y·lase/ (am´ĭ-lās) an enzyme that catalyzes the hydrolysis of starch into simpler compounds. The α-a's occur in animals and include pancreatic and salivary amylase; the β-a's occur in higher plants.

amylase

(ăm′ə-lās′, -lāz′)

n.

Any of a group of enzymes that catalyze the hydrolysis of starch to sugars. In humans, amylases are produced in the salivary glands and the pancreas.

amylase

[am′ilās]

Etymology: Gk, amylon, starch

an enzyme that catalyzes the hydrolysis of starch into smaller carbohydrate molecules. Alpha-amylase, found in saliva, pancreatic juice, malt, certain bacteria, and molds, catalyzes the hydrolysis of starches to dextrins, maltose, and maltotriose. Beta-amylase, found in grains, vegetables, malt, and bacteria, is involved in the hydrolysis of starch to maltose. Normal blood findings are 56 to 190 IU/L.

amylase

An enzyme synthesised in the pancreas and salivary glands and secreted in the GI tract which digests starch and glycogen. It is measured in patients with suspected pancreatitis: serum and urine levels peak 4–8 hours after onset of acute pancreatitis, and normalise within 48–72 hours. Parotitis due to mumps or radiation therapy also increases serum amylase; cases of increased serum amylase without obvious pancreatitis or parotitis require quantification of amylase isoenzymes.
 
Amylase increased in
Acute pancreatitis; obstruction of common bile duct, pancreatic duct or ampulla of Vater; pancreatic injury from perforated peptic ulcer; pancreatic cancer; acute salivary gland disease.

Amylase reduced in
Chronic pancreatitis, pancreatic cancer, cirrhosis, hepatitis, eclampsia.

amylase

Clinical chemistry An enzyme synthesized in the pancreas and salivary glands and secreted in the GI tract, which digests starch and glycogen; amylase is measured in Pts with suspected pancreatitis; serum and urine levels peak 4-8 hrs after onset of acute pancreatitis, and normalize within 48-72 hrs; parotitis due to mumps or radiation therapy also ↑ serum amylase; in cases of ↑ serum amylase without pancreatitis or parotitis, requires quantification of amylase isoenzymes Ref range Varies by laboratory; 25-90 U/L, serum; 4-30 U/2 hrs, urine; amylase is ↑ in acute pancreatitis, obstruction of common bile duct, pancreatic duct or ampule of Vater, pancreatic injury from perforated peptic ulcer, acute salivary gland disease; amylase is ↓ in chronic pancreatitis, pancreatic CA, cirrhosis, hepatitis, eclampsia. See Macroamylase.

am·y·lase

(am'il-ās)

One of a group of amylolytic enzymes that cleave starch, glycogen, and related 1,4-α-glucans.

amylase

An ENZYME that converts starch to simpler carbohydrates such as disaccharides and small polysaccharides.

Fig. 33 Amylase . The splitting of starch to form maltose.

amylase

a digestive enzyme which enables starch to be split by hydrolysis into smaller subunits of MALTOSE, usually in alkaline conditions (see Fig. 33 ).

Amylases are found in the saliva of most mammals (and were previously called ptyalin). Their functioning is limited to the brief time that food remains in the mouth. Once food is swallowed, the acid stomach conditions prevent further amylase activity. The principal location of starch digestion is in the duodenum, where pancreatic amylase is poured into the gut lumen from the pancreas as part of the pancreatic juice; pancreatic amylase has a greater digestive efficiency than salivary amylase. Amylases are common in plants, particularly in association with the starch stores of seeds and underground perennating organs such as rhizomes, tubers and taproots. Amylases are also produced by MICROORGANISMS such as BACILLUS, STREPTOMYCES and the fungus Aspergillus, and are used in the food industry.

Amylase

A digestive enzyme made primarily by the pancreas and salivary glands.

Mentioned in: Amylase Tests, Lipase Test

amylase (am´ilās),

n an enzymatic protein essential for changing starches into sugars.

amylase

an enzyme that catalyzes the hydrolysis of starch into simpler compounds. The α-amylases occur in animals and include pancreatic and salivary amylase; the β-amylases occur in higher plants. Measurement of serum α-amylase activity is an important diagnostic test for acute pancreatitis and acute attacks of chronic pancreatitis.

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amylase isoenzymes

serum amylase is composed of a number of isoenzymes, isoamylases, probably originating from different tissues. Elevation of an isoenzyme of hepatic origin is found in hyperadrenocorticism.

amylase reaction

an identification test, based on an extracellular product of group A β-hemolytic streptococci.

serum amylase

the most significant laboratory aid in the diagnosis of acute pancreatitis or exacerbations of a chronic pancreatitis. Other organs may also produce the enzyme, or its isoenzymes, but the amounts are normally limited.

urine amylase

dogs excrete very little amylase in the urine in contrast to humans where urine levels of the enzyme may be valuable in assessing the progress of a case of pancreatitis.