Striatal Dopamine Release Regulation by the Cholinergic Properties of the Smokeless Tobacco, Gutkha

Abstract

Tobacco products influence striatal dopamine (DA) release primarily through the actions of nicotine, an agonist of nicotinic acetylcholine receptors (nAChR). Gutkha is a smokeless tobacco product that contains not only nicotine, but also the habit-forming areca nut and other plant-based constituents that contribute muscarinic acetylcholine receptor (mAChR) agonists and other cholinergic agents. Thus, the net influence of the cholinergic agents in gutkha on striatal DA release difficult to predict. This study investigated the influence of gutkha extract on evoked DA release in mouse striatal slices using fast-scan cyclic voltammetry. The potency of a given concentration of nicotine in the gutkha extract was found to be significantly lower than that of a comparable concentration of nicotine alone. Atropine, a mAChR antagonist, increased the potency of gutkha-associated nicotine; however, other experiments suggested that this was mediated in part by direct effects of atropine at nAChRs. Overall, these results suggest that the unique constituents of gutkha work together to oppose the influence of gutkha-associated nicotine on evoked striatal DA release.

Cytological and cytomorphometric characteristics of buccal mucosa cells from smokeless tobacco users

“…Most ST products contain hazardous substances, such as nicotine, cadmium, and nitrosamines. 1 ST and some additives have been reported to have adverse effects on the oral mucosa, teeth and gingiva, 22 central nervous system, 23 cardiovascular system, 24 and digestive and urinary systems. 1 ST is also associated with a high prevalence of oral carcinoma, for example, in India.…”