110 likes | 386 Views
Reactivation of Phosphorylated Acetylcholinesterase. Oximes are used to reactivate phosphorylated AChE The group (=NOH) has a high affinity for the phosphorus atom Pralidoxime has a nucleophilic site that interacts with the phosphorylated site on phosphorylated-AChE.
E N D
Reactivation of Phosphorylated Acetylcholinesterase Oximes are used to reactivate phosphorylated AChE The group (=NOH) has a high affinity for the phosphorus atom Pralidoxime has a nucleophilic site that interacts with the phosphorylated site on phosphorylated-AChE
Pralidoxime Reacts Chemically with Phosphorylated-AChE The oxime group makes a nucleophilic attack upon the phosphorus atom
Limitations of Pralidoxime Pralidoxime does not interact with carbamylated-AChE Pralidoxime in high doses can inhibit AChE Its quaternary ammonium group does not allow it to cross the blood brain barrier “Aging” of phosphorylated-AChE reduces the effectiveness of pralidoxime and other oxime reactivators
Other Cholinesterase Reactivators Diacetylmonoxime Crosses the blood brain barrier and in experimental animals, regenerates some of the CNS cholinesterase HI-6 is used in Europe Has two oxime centers in its structure More potent than pralidoxime
Edrophonium is a Short Acting Inhibitor that Binds to the Ionic Site but Not to the Esteratic Site of AChE
Inhibition of Acetylcholinesterase Produces Stimulation of All Cholinergic Sites
Carbamyl Inhibitors of AChE Physostigmine Neostigmine (N+) Pyridostigmine (N+) Ambenonium (N+) Demecarium (N+) Carbaryl