What type of receptor does mecamoamine block selectively?

Mecamylamine is a drug that selectively blocks nicotinic receptors, which are a type of acetylcholine receptor found in both the central and peripheral nervous systems. These receptors are important for mediating the effects of the neurotransmitter acetylcholine at synapses in the autonomic ganglia and at the neuromuscular junction, as well as in various areas of the brain. By blocking nicotinic receptors, mecamylamine can inhibit the actions of acetylcholine, leading to effects such as reduced muscle contraction and altered neurotransmission in ganglia, impacting autonomic functions.

This selective action on nicotinic receptors makes mecamylamine distinct from the other types of receptors listed. Muscarinic receptors, for example, are another class of acetylcholine receptors but are primarily involved in the parasympathetic nervous system. Adrenergic receptors respond to epinephrine and norepinephrine, while opioid receptors are involved in pain modulation and are not affected by mecamylamine. The specificity of mecamylamine for nicotinic receptors is what underscores its role and expected therapeutic effects in clinical and experimental settings.