The inhibition of acetylcholinesterase and pseudocholinesterase by cimetidine.
Cimetidine inhibited cholinesterases from human blood serum, erythrocytes, brain and gastric mucosa in a dose-dependent manner. The median inhibitory concentrations ranged between 7.0 x 10(-4) mol/l and 2.1 x 10(-3) mol/l. The inhibition was of competitive type, the inhibitory constant of acetylcholinesterases in erythrocytes were found to be 8.5 x 10(-5) mol/l and of pseudocholinesterases in serum 8.5 x 10(-4) mol/l. A significance of our findings may be the explanation of side effects seen in cimetidine overdosage.
D000110:Acetylcholinesterase; D001667:Binding, Competitive; D001921:Brain / Q000201:enzymology; D002091:Butyrylcholinesterase; D002800:Cholinesterase Inhibitors; D002927:Cimetidine / Q000494:pharmacology*; D004912:Erythrocytes / Q000201:enzymology; D005753:Gastric Mucosa / Q000201:enzymology; D006146:Guanidines / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics
D002800:Cholinesterase Inhibitors; D006146:Guanidines; D002927:Cimetidine; D000110:Acetylcholinesterase; D002091:Butyrylcholinesterase