IADR Abstract Archives
Smoking Can Affect Bitter, Sweet, Umami Taste Receptors Gene Expression
Objectives: Nicotine in tobacco decreases food intake and body weight by influencing the hypothalamic melanocortin system. However, little has been reported on direct effects of smoking on the taste receptors. In this study, we compared the gene expression of bitter, sweet and umami taste receptors in the tongue in smokers with those in non-smokers.
Methods: The subjects were comprised of 10 male smokers (the mean number of cigarettes smoked daily: 8.7 ± 2.8) and 12 male non-smokers aged 20 to 28 who have healthy condition and normal recognition thresholds of five basic tastes (sweet, salty, bitter, sour and umami) assessed by the filter-paper disk method. Tissue samples were collected from the foliate papillae by scraping their tongue. Gene expression analysis were performed by real-time polymerase chain reaction of β-actin, gustducin, bitter taste receptors (TAS2R3, TAS2R4, TAS2R10 and TAS2R40) with high homology to the T2R genes, sweet taste receptor (T1R2/T1R3) and umami taste receptor (T1R1/T1R3). Gene expression of above receptors was statistically compared between smokers and non-smokers.
Results: In smokers, TAS2R3 and TAS2R40 out of the four bitter receptor genes showed a significant increase in the frequency of detection of the gene expression as compared with non-smokers, while there was no significant differences in amount of the gene expression of the four bitter taste receptors between them. The mean expression of T1R3 in smokers was significantly higher than that in non-smokers, indicating that smoking could induce the alteration of sensitivity to sweet and umami taste receptors.
Conclusions: Smoking does directly affect the gene expression of bitter, sweet and umami taste receptors. These results suggests that the sensation of bitter, sweet and umami taste could be altered by smoking.
Methods: The subjects were comprised of 10 male smokers (the mean number of cigarettes smoked daily: 8.7 ± 2.8) and 12 male non-smokers aged 20 to 28 who have healthy condition and normal recognition thresholds of five basic tastes (sweet, salty, bitter, sour and umami) assessed by the filter-paper disk method. Tissue samples were collected from the foliate papillae by scraping their tongue. Gene expression analysis were performed by real-time polymerase chain reaction of β-actin, gustducin, bitter taste receptors (TAS2R3, TAS2R4, TAS2R10 and TAS2R40) with high homology to the T2R genes, sweet taste receptor (T1R2/T1R3) and umami taste receptor (T1R1/T1R3). Gene expression of above receptors was statistically compared between smokers and non-smokers.
Results: In smokers, TAS2R3 and TAS2R40 out of the four bitter receptor genes showed a significant increase in the frequency of detection of the gene expression as compared with non-smokers, while there was no significant differences in amount of the gene expression of the four bitter taste receptors between them. The mean expression of T1R3 in smokers was significantly higher than that in non-smokers, indicating that smoking could induce the alteration of sensitivity to sweet and umami taste receptors.
Conclusions: Smoking does directly affect the gene expression of bitter, sweet and umami taste receptors. These results suggests that the sensation of bitter, sweet and umami taste could be altered by smoking.