PANCREATIC ENZYMES Flashcards
PANCREATIC ENZYMES
▪
AMYLASE
LIPASE
AMYLASE (AMS)
EC
▪ E.C. 3.2.1.1
▪ 1,4-D-Glucan Glucanohydrolase
AMS function
▪ Breakdown of starch and glycogen to monosaccharides
AMS
▪ Activators:
Calcium and chloride
AMYLASE (AMS)
Tissue Sources
– Salivary glands
▪ Salivary AMS or ptyalin
– Acinar cells of the pancreas
▪ Pancreatic AMS
AMYLASE (AMS)
Properties
– MW_____
– Readily filtered by the
50,000 – 55,000
glomerulus
– initial digestion of starch by salivary AMS
▪ Inactivated in the______
– final digestion by pancreatic AMS
Mouth; stomach
Small intestine
AMYLASE (AMS)
Isoenzymes
P-type isoamylase
S-type isoamylase
Pancreas
P-type isoamylase that is predominant in Acute pancreatitis
P3
Stype AMS found in
▪ Salivary gland
▪ Lungs
▪ Fallopian tubes
AMYLASE (AMS)
Diagnostic Significance
What disease?
▪ Rise:
▪ Peak:
▪ Normalize:
– Acute Pancreatitis
5-8 hours after the onset of an attack
24 hours
3-5 days
AMYLASE (AMS)
Diagnostic Significance
– Acute Pancreatitis
– Salivary gland lesions (parotitis)
– Intra-abdominal diseases
Chronic alcohol ingestion results in the:
– Secretion of protein-rich pancreatic fluid that leads to the deposition of thickened protein plugs and obstruction of small pancreatic ducts
– Transient increase in the pancreatic exocrine secretion and contraction of the sphincter of Oddi
– Direct toxicity in the acinar cells
AMYLASE (AMS)
Diagnostic Significance
– persistent increase in serum amylase is seen without clinical symptoms
Macroamylasemia
LIPASE (LPS)
EC
▪ E.C. 3.1.1.3
▪ Triacylglycerol Acylhydrolase
LIPASE function
Hydrolyzes the ester linkages of fats to produce alcohols and fatty acids
LIPASE (LPS)
Tissue Sources
– Primarily in the pancreas
– Also present in liver, stomach, small intestine, white blood cells, fat cells and milk (Henry)
LIPASE (LPS)
Diagnostic Significance
– Almost exclusive to the diagnosis of____
▪ Rise:
▪ Peak:
▪ Persist for about
▪ ____rise suggests poor prognosis or pancreatic cyst
acute pancreatitis
4-8 hours after onset of an attack
24 hours
8-14 days
> 14 days
LIPASE (LPS)
Diagnostic Significance
– Found also in other intra-abdominal conditions
______
– Normal in conditions with_____
▪ Duodenal ulcers, perforated peptic ulcers, intestinal obstruction, acute cholecystitis
salivary gland involvement
LIPASE (LPS)
▪ MW :
▪ Enzymatic activity is specific for the fatty acid residues at positions _____of the TAG molecules
▪ Substrate must be an_____ for activity to occur
45,000
1 and 3
emulsion
LIPASE
▪ Reaction rate is accelerated by the presence of
colipase and bile salt
LIPASE (LPS)
– Inhibit serum lipase
▪ Proteins, bile acids, heavy metals, quinine, and phospholipids
LIPASE
– Reverse this inhibition
– Coenzyme that prevents inhibitory effects on lipase
▪ Colipases
Macroamylasemia
– AMS molecule combines with…
IgG or IgA
