Question

_______ acts at both nicotinic and muscarinic receptors.

• A. \( \text{Acetylcholine} \)
• B. \( \text{Atropine} \)
• C. \( \text{Hyoscyamine} \)
• D. \( \text{Tubocurarine} \)

Hint:

Acetylcholine is the primary neurotransmitter of the parasympathetic nervous system and acts as the endogenous ligand for both types of cholinergic receptors.

Answer 1

The Correct Option is A

Acetylcholine is a neurotransmitter that binds to and activates both nicotinic and muscarinic cholinergic receptors. Nicotinic receptors are ligand-gated ion channels, while muscarinic receptors are G protein-coupled receptors. Atropine and hyoscyamine are muscarinic receptor antagonists. Tubocurarine is a nicotinic receptor antagonist, specifically a neuromuscular blocker.