title: Influence of atropine upon ageing and reactivation of soman inhibited acetylcholinesterase from human erythrocytes. Preliminary communication.
abstract: From human blood concentrates erythrocyte "ghosts" were prepared. These and an enzyme solution, obtained by Triton X 100 treatment of the ghosts, were reacted with 1.2.2-trimethylpropyl-methyl-phosphonylfluoridate (soman). The rate constants of inhibition of the membrane bound and solubilized acetylcholinesterase (AChE) were determined at 3 degrees C, pH 8 and 9 to be 2 X 10(7) and 1.4 X 10(7) mol-1 min-1, respectively. Ageing of the phosphonylated AChE occurred with rate constants of 3.5 X 10(-2) (ghost bound) and 1.3 X 10(-2) (solubilized) min-1 at 3 degrees C, pH 8. 5 X 10(-4) mol/l atropine decreased the ageing rate by 50%. Reactivation of the non aged phosphonyl-AChE by several pyridinium oximes was enhanced by atropine with the ghost-bound enzyme; the reactivation of the phosphonylated solubilized enzyme, however, was not affected by atropine.
mesh_terms: D000110:Acetylcholinesterase; D001285:Atropine / Q000494:pharmacology*; D002800:Cholinesterase Inhibitors / Q000494:pharmacology*; D002801:Cholinesterase Reactivators / Q000494:pharmacology*; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D012999:Soman / Q000494:pharmacology*
chemical_list: D002800:Cholinesterase Inhibitors; D002801:Cholinesterase Reactivators; D001285:Atropine; D012999:Soman; D000110:Acetylcholinesterase