Chemical E, a chemical that mimics the function of acetylcholine, could not serve as a muscle relaxer. We can determine this through understanding the function of acetylcholine in the body—specifically, the function of acetylcholine on skeletal muscles. Acetylcholine is a neurotransmitter, which means that it is a chemical released by a nerve cell or neuron that relays neural impulses throughout the central nervous system (CNS) and the peripheral nervous system (PNS) via synapses, which facilitates communication and facilitates motor function. Acetylcholine is a neurotransmitter that causes muscles to contract, activates pain responses, and regulates endocrine and REM sleep functioning.
A chemical that mimics the function of acetylcholine, then, would facilitate muscle movement rather than relaxation. As such, one would need to use a chemical that functions in an opposing manner to acetylcholine in order to function as a muscle relaxer. A chemical that inhibits acetylcholine from attaching to the polypeptide nicotinic acetylcholine receptors, or nAChRs, could serve as a muscle relaxer and could serve to inhibit the function of acetylcholine on skeletal muscles without inhibiting the function of acetylcholine on other areas of the body. For instance, inhibiting acetylcholine on the nicotinic acetylcholine receptors should not cause acetylcholine from being able to transmit neural impulses that regulate the function of the heart.