Nicotine activates a channel known to be involved in inflammatory responses reports a study published online this week in Nature Neuroscience. This ion channel is found in the skin and the lining of the nose and mouth, and it may be the source of the irritating side effects of nicotine replacement therapies.
It had been thought that the irritation from nicotine patches and other replacement treatments resulted from the stimulation of nicotinic receptors on the nerves that convey painful stimuli from the skin and the linings of the nose and mouth. However, Talavera and colleagues report that, in mice, nicotine also directly activates TRPA1, a channel known to convey information about irritating substances and inflammatory pain. The authors also report that mice lacking TRPA1 show no irritation in response to the intra-nasal administration of nicotine.
This finding may help in the development of therapies which help stop people smoking with fewer adverse effects.