Acetylcholinesterase in the skeletal muscle endplate region. Acetylcholinesterase (AChE) is responsible for terminating the effect of acetylcholine on nicotinic receptors in the end plate region by hydrolyzing acetylcholine to choline and acetate. These inactive metabolites are taken up by the presynaptic nerve terminal and recycled. In the presence of a cholinesterase inhibitor, the metabolism of acetylcholine is reduced, resulting in an accumulation of acetylcholine and a prolonged and more intense effect. The same events also occur in tissues expressing muscarinic receptors (e.g. the heart, lungs, eye, lacrimal glands, GI tract).