Adaptation of neuromuscular junction to transmission of impulses after inactivation of acetylcholinesterase.

Adaptation of neuromuscular junction to transmission of impulses after inactivation of acetylcholinesterase. Acta Physiol. Pol., 1977, 28 (1): 23-30. Isolated preparation of rat diaphragm with phrenic nerve was incubated in paraoxon solutions which caused complete inactivation of acetylcholinesterase. This inactivation was associated with disturbances of neuromuscular transmission in the form of blockade of the tetanic response, post-tetanic inhibition of twitch responses and a decreased amplitude of the second response after the first one when two stimuli at a short interval were used. These disturbances were withdrawn somewhat during further incubation of the preparation, although it was kept in paraoxon solution which maintained complete inactivation of acetylcholinesterase. It is suggested that the observed recession of transmission disturbances may be caused by partial adaptation of blockade of the tetanic response, post-tetanic inhibition of twitch blockade of enzymatic hydrolysis of acetylcholine.