Clinical and experimental pharmacology & physiology
-
Clin. Exp. Pharmacol. Physiol. · Jan 1982
Comparative StudyFurther comparison of the effects of physostigmine and neostigmine on frog neuromuscular transmission.
1. The effects of physostigmine and neostigmine were compared at frog neuromuscular junctions using intracellular microelectrodes. 2. Both drugs increased the amplitudes of miniature endplate potentials (MEPP) in a dose-dependent manner because of their ability to competitively inhibit cholinesterase activity. 3. ⋯ Similar results were obtained with physostigmine. 6. Neither drug significantly affected MEPP frequency although small decreases were sometimes observed. 7. These results suggest that at the frog neuromuscular junction the effects of neostigmine are explained primarily by its inhibition of cholinesterase, whereas physostigmine are explained primarily by its inhibition of cholinesterase, whereas physostigmine has an additional action on nerve terminals of decreasing nerve-stimulated release of acetylcholine.