A patient complains of muscle weakness. It was reversed on the administration of neostigmine, because:
It blocks action of acetylcholine
It interferes with the action of mono amine oxidase
It interferes with the action of carbonic anhydrase
It interferes with the action of acetylcholine esterase.
Neostigmine acts by inhibiting the enzyme acetylcholinesterase. This enzyme is involved in degradation of ACh, conse­quently neostigmine increases the synaptic level of ACh. Muscle weakness can be improved by stimulation of NM recep­tors at muscle end plate due to increased ACh.