toxin and toxicant response pathway nicotine response pathway 2014-03-28T10:56:10Z A pathway triggered by exposure to nicotine, the alkaloid found in tobacco and other plants. Nicotine can act as a stimulant and is an agonist of the ionotropic acetylcholine receptors, also known as nicotinic. Sustained exposure however has an inhibitory effect resulting in muscular paralysis, seizures, hypotension and respiratory failure. Some of the symptoms are reminiscent of organophosphate poisoning; organophosphates inhibit the enzyme acetylcholinesterase leading to uncensored stimulation of both the nicotinic and the metabotropic muscarinic acetylcholine receptors. PW:0001523 pathway vpetri