Diisopropylfluorophosphate: Suppression of Ionic Conductance of the Cholinergic Receptor
K. Kuba 1,
E. X. Albuquerque 1, and
E. A. Barnard 2
1 Department of Pharmacology, Schools of Medicine and Dentistry, State University of New York at Buffalo, Buffalo 14214
2 Department of Biochemistry, State University of New York at Buffalo
When frog sartorius muscles were exposed to diisopropylfluorophosphate, the amplitude and half-decay time of the end-plate current decreased; the half-decay time became almost potential-independent and the equilibrium potential for the end-plate current was more negative than during control conditions. When the excess reagent was removed by washing so that only the phosphorylated acetylcholinesterase remained, the amplitude of the end-plate current was restored, while its half-decay time was markedly increased. These findings reveal that this organophosphate significantly affects the receptor-ionic conductance modulator complex in addition to its well-known anticholinesterase activity.
