Nicotinic Receptor

 

3.4. Nicotinic receptor agonists

natural alkaloid found in tobacco which mimics the effects of ACh at nicotinic receptors at:

autonomic ganglionic synapses (both SNS and PNS)

skeletal  neuromuscular junctions

-nicotine is still used in some insecticides

clinical use:

-no therapeutic action but important for its toxicity-available as a transdermal patch or as chewing gum-used as an aid in the cessation of smoking

Toxicity:

-both stimulant and depressant (affects both SNS and PNS ganglia)- stimulates nicotinic receptors in CNS ----> mild alerting action-also acts centrally ----> tremor and convulsions-can increase or decrease HR-increased respiratory rate- vomiting due to activation of chemoreceptor trigger zone-larger doses ----> CNS and respiratory depression by muscle endplate depolarization blockade