esterases

what factors are required for optimal in vitro activity of pancreatic lipase

bile salts, bile acids, and colipase

what are the major tissue sources of ALP

bone, liver, kidney, placental, intestinal

what method could be used to measure SChE

butyrylthiocholine

what cofactors does alpha amylase require

calcium (chloride for optimal activity)

what reactions do choline esterase catalyze

catalyze hydrolysis of choline esterase

what reaction does alkaline phosphatase catalyze

catalyzes hydrolysis of phosphate esters at an alkaline pH

what reaction does alpha amylase catalyze

catalyzes the hydrolysis of alpha 1,4 glycosidic bonds

what is the most common method for measuring serum lipase activity

colorimetric method

where is acetylcholinesterase found and what is it important for

found in the brain, RBCs, lungs, spleen, nerve endings. important for proper nerve and neuromuscular transmission

AA genotypes are _____ susceptible to __________ inhibition

less; dibucaine

FF genotypes are ____ susceptible to _________ inhibition

less; fluoride

what reaction does lipase catalyze

lipase catalyzes the hydrolysis of dietary triglycerides with long chain fatty acids

where is pseudocholinesterase found

liver, pancreas, heart, brain, and very high levels in the plasma

how is thermal inactivation used to measure increases in serum ALP

measure ALP, incubate at 56C for 10 minutes, then remeasure -bone: less than 20% remains after incubation -liver: 25-55% remains after incubation ->55% = Regan isoenzyme

what is the normal amylase/creatinine clearance ratio and when would it be increased/decreased

normal: 2-5% increased: acute pancreatitis decreased: macroamylasemia

what are the major tissue sources of alpha amylase

pancreas and salivary glands

when is serum SChE decreased

pesticide poisoning (can be decreased by 40% before symptoms are seen, serious neuromuscular damage can happen once SChE is decreased by 80%)

what is the Regan isoenzyme

placental type isoenzyme associated with tumors

name conditions that could lead to increased serum ALP levels

pregnancy, growing children, hepatocellular disease, posthepatic obstruction

how do organic phosphates, dibucaine and fluorides affect SChE activity

they all inhibit SChE activity (fluoride and dibucaine are inhibitors of the normal genotype UU)

what cofactors does ALP require

zinc and magnesium

what is the generic reference range for ALP

20-100 I.U./L

what is the generic reference range for SChE

4,000-12,000 I.U./L

what is the most common method for measuring serum ALP

4-nitrophenolphosphate

what is the optimal pH for alpha amylase

6.9-7.0

serum lipase activity is important for the differential diagnosis of what

acute abdominal pain

when is serum lipase activity increased

acute pancreatitis

when is serum amylase increased

acute pancreatitis, pancreatic trauma/cancer, opiates(morphine), macroamylasemia

how the levels of AChE compare in acute vs chronic pesticide poisoning

acute= RBC AChE is normal chronic= both RBC AChE and serum SChE are decreased