Acetylcholinesterase (1)

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Acetylcholinesterase (1)

• Sites of location
• Cholinergic neurons
• Cholinergic synapses
• Neuromuscular junction
• Red blood cells
• Substrates
• Acetylcholine is the best substrate
• Methacholine is a substrate
• Hydrolyzes ACh at greater velocity than choline
  esters with acyl groups larger than acetate or
  proprionate

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Acetylcholinesterase (2)

• Esters that are not substrates
• Bethanechol
• Carbachol
• Succinylcholine
• Its inhibition produces synergistic interaction
  with methacholine and additive actions with
  bethanechol and carbachol
• Drugs that block its hydrolysis of esters are
  called cholinesterase inhibitors

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Drug Interactions of Choline Esters and
Inhibitors of Acetylcholinesterase - Synergism
versus Additivity

• Methacholine
• Carbachol
• Bethanechol

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Butyrylcholinesterase
(Plasma esterase, pseudocholinesterase, serum
esterase, BuChE, PseudoChE)
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Butyrylcholinesterase (1)

• Sites of location
• Plasma, liver, glial cells, other tissues
• Substrates
• Butyrylcholine is the best
• Acetylcholine
• Succinylcholine
• Procaine

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Butyrylcholinesterase (2)

• Esters that are not substrates
• Methacholine, bethanechol, and carbachol
• Is inhibited by carbamyl and organophosphate
  inhibitors of acetylcholinesterase

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Active Site of Acetylcholinesterase
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Interaction of AChE and Acetylcholine
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(No Transcript)
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Acetylation of AChE and Release of Choline
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Hydroxyl Group of Water Attacks the Carbonyl
Group of Acetylated-AChE to Liberate AChE
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Carbamyl Inhibitors of AChE