Nicotine effect on chromaffin cells (Homo sapiens)

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Nicotine is an alkaloid found in tobacco plants. It is a substance that acts as a stimulant in humans and is one of the main factors responsible for tobacco dependence. When nicotine enters the body, it is distributed quickly through the bloodstream, and it can cross the blood-brain barrier to enter the central nervous system (CNS). It binds to two main types of nicotinic acetylcholine receptors: the ganglion type and the CNS type.

In chromaffin cells in the adrenal medulla, nicotine binds to the ganglion-type nicotinic acetylcholine receptor, which is composed of alpha 3 (CHRNA3) and beta 4 (CHRNB4) subunits. By binding to the receptors, nicotine causes cell depolarization and an influx of calcium through voltage dependent calcium channels. Calcium triggers the release of epinephrine from the chromaffin vesicles into the bloodstream, which leads to increased heart rate and blood pressure and elevation of blood glucose level.

Sources: PharmGKB:Nicotine in Chromaffin Cells, Wikipedia:Nicotine